Filed 4/4/24 Nalick v. Seagate Technology CA1/1

NOT TO BE PUBLISHED IN OFFICIAL REPORTS

California Rules of Court, rule 8.1115(a), prohibits courts and parties from citing or relying on opinions not certified for 

publication or ordered published, except as specified by rule 8.1115(b). This opinion has not been certified for publication or 

ordered published for purposes of rule 8.1115. 

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIRST APPELLATE DISTRICT

DIVISION ONE

SCOTT NALICK,

 Plaintiff and Appellant,

 v.

SEAGATE TECHNOLOGY LLC,

 Defendant and Respondent.

 

A166356

(San Francisco City & County

Super. Ct. No. CGC-15-547787)

Plaintiff Scott Nalick, on behalf of himself and others similarly 

situated, appeals from an order decertifying a class alleging violations of the 

Consumer Legal Remedies Act (Civ. Code, § 1750 et seq.; CLRA) and 

California’s unfair competition law (Bus. & Prof. Code, § 17200 et seq.; UCL) 

under an omissions-based theory of liability. We affirm.

I.

INTRODUCTION

In June 2017, Nalick filed the operative second amended complaint 

(SAC) on behalf of a putative class of purchasers of defendant Seagate 

Technology LLP’s (Seagate) three-terabyte hard disk drives bearing model 

No. ST3000DM001 (the Drives). In November 2017, the trial court granted 

in part Nalick’s motion for class certification—certifying only as to CLRA and 

UCL claims based on Seagate’s alleged omissions of the Drives’ failure rates. 

Regarding predominance, the court ruled that Seagate’s knowledge of the 
2

Drives’ annual failure rates (AFR), reasonable consumers’ expectations of the 

Drives’ failure rates, and the Drives’ actual AFRs were all susceptible to 

common proof. Despite lacking evidence of the Drives’ actual AFRs, the court 

reasoned Nalick “may be able to demonstrate that whatever the failure rate 

was—and by definition, there was some failure rate, there always is—it was 

sufficiently high that consumers should have been alerted to it.” After the 

ruling, the parties stipulated the class and subclass definitions. 

In April 2019, the trial court denied a motion by Seagate for summary 

adjudication, but later granted Seagate’s motion for reconsideration and 

reversed its previous decision. Nalick appealed, and this court reversed the 

order granting summary adjudication in a nonpublished opinion. (Nalick v.

Seagate Technology LLC (Mar. 25, 2021, A158237) (Seagate I).) Our opinion 

addressed Seagate’s duty to disclose under the CLRA and UCL, and 

concluded the evidence was sufficient to show the materiality of an AFR as 

low as 1 percent as well as Seagate’s knowledge of the allegedly high AFR. 

On remand, Seagate moved to decertify the class, challenging 

predominance, typicality, and ascertainability. Nalick opposed the motion,

arguing Seagate did not meet its burden to establish changed circumstances 

necessary for class decertification and, alternatively, common issues 

predominated the case and the class was still ascertainable.

The trial court granted the decertification motion. The court 

determined the motion was procedurally proper because it was “predicated on 

different arguments and evidence than [Seagate’s] opposition to class 

certification” and because a federal court in a similarly situated case denied 

certification of a nationwide class. In light of Nalick’s claims “rely[ing] on 

AFR to establish the predicate fact that the Drives had a high failure rate,”

the court found Seagate’s newly submitted evidence demonstrated “the 
3

measure of AFR itself [was] subject to individualized inquiries.” After also 

excluding an expert declaration submitted in support of Nalick’s opposition 

briefing, the court concluded Nalick failed to meet his burden to show that 

common issues predominate, the class action was manageable, and the class 

was sufficiently ascertainable. Nalick appealed. 

We find no abuse of discretion and affirm. 

II.

FACTUAL AND PROCEDURAL BACKGROUND

Seagate manufactures the Drives, which are used in multiple different

products and serve different needs. Seagate publicly represented that the 

Drives provide “ ‘trusted performance, reliability, simplicity and capacity’ ” to 

protect against data loss.

Nalick purchased a product containing one of the Drives, which failed 

approximately one year later, causing Nalick to lose his data. This was, he 

claims, because the Drives “contain[ed] latent defects that cause the Drives to 

fail at an extraordinarily high rate.” In 2017, after overcoming Seagate’s 

demurrer, Nalick filed the operative SAC asserting Seagate’s alleged 

misrepresentations and omissions about the Drives’ failure rates violated the 

CLRA, UCL, California’s false advertising law (Bus. & Prof. Code, § 17500 et 

seq.), and the Song-Beverly Consumer Warranty Act (Civ. Code, § 1790 et 

seq.) He also filed a motion for class certification for the alleged violations of 

the Song-Beverly Act, UCL, and CLRA.

A. Class Certification

In his motion for class certification, Nalick characterized the “core 

issues of liability” as “whether the Drives were suitable for their ordinary 

purpose and whether Seagate’s conduct was deceptive.” To prove the Drives 

were unfit for their ordinary purpose, Nalick presented evidence of (1) a 
4

“study of over 50,000 consumer-grade hard drives that showed that the 

Drives failed at a 78% rate,” and (2) a recall of “OEM” products that used the 

Drives due to a three-year cumulative return rate of around 5 percent.

1 

Nalick did not allege the exact failure rate of the Drives, but his expert,

Thomas Coughlin, testified by declaration that Seagate “quantifies failure 

rates using a metric known as ‘Annual Failure Rate’ or ‘AFR.’ ” As both 

Coughlin and Seagate explained, AFR is an estimated percentage a product 

will fail due to a manufacturer issue within one year. AFR measures the 

statistical reliability of the Drives as manufactured, before Seagate 

distributes or sells them. 

Seagate’s opposition attacked Nalick’s alleged common proof—i.e., the

study purporting a 78 percent failure rate and a recall of OEM products due 

to postsale returns. Specifically, Seagate argued there was no evidence of 

any alleged common “defect” in the Drives and “no [admissible] evidence that 

the proposed class experienced a failure rate similar to the one” claimed by 

the study or OEM recall. (Italics omitted.)

In November 2017, the trial court partially granted Nalick’s motion for 

class certification to certain CLRA and UCL claims based on alleged 

omissions of the Drives’ failure rates. Its finding that common issues 

predominated was premised on the fact “there was some failure rate.” The 

court explained Nalick would need “to demonstrate that whatever the failure 

rate was and, by definition, there was some failure rate, there always is — it 

was sufficiently high that consumers should have been alerted to it.” The 

court denied the motion as to the other claims, in part because Nalick failed 

1 OEM products are ones in which the Drives are only a single 

component, such as a hard drive installed inside a desktop computer. OEM 

products were not included in the class definition. 
5

to present substantial evidence of a defect or affirmative misrepresentations 

in Seagate’s advertising. 

B. This Court Reverses Summary Adjudication2

Following the grant of class certification, Seagate moved for summary 

adjudication, which was denied in April 2019. But about two months after 

initially denying Seagate’s motion, the trial court reconsidered and reversed 

its prior opinion. The court held on reconsideration that Nalick’s evidence 

was not sufficient to show a dispute of material fact regarding what AFR

would be material to a reasonable consumer. And the court found Seagate’s 

evidence failed to demonstrate knowledge of an AFR above 3 percent. On 

appeal, we reversed. (Seagate I, supra, A158237.)

First, we held the trial court improperly interpreted Daugherty v. 

American Honda Motor Co., Inc. (2006) 144 Cal.App.4th 824 as a bar to

Seagate’s liability for omissions after the expiration of the warranty period. 

We explained California law “sanctioned an ‘omission claim when: the 

plaintiff alleges that the omission was material; second, the plaintiff [alleges]

the defect was central to the product’s function; and third, the plaintiff 

[alleges] one of the four LiMandri[3]factors.’ ” (Seagate I, supra, A158237.) 

Because the Drives’ alleged defect—i.e., their high rate of failure—related to 

the Drives’ central functionality, we determined Nalick’s claims could proceed 

“provided he can meet the LiMandri test and demonstrate materiality and 

exclusive knowledge by Seagate.” (Ibid.) 

2 We incorporate by reference the procedural and factual background 

detailed in our previous nonpublished opinion, Seagate I, supra, A158237. 

But because the parties dispute its import, we summarize our prior opinion 

and then describe the subsequent procedural history. 

3 LiMandri v. Judkins (1997) 52 Cal.App.4th 326 (LiMandri).
6

Regarding the LiMandri test, we held Nalick may demonstrate a duty 

to disclose arising from Seagate’s alleged partial representations about the 

Drives’ reliability. In short, the fact that the certified class claims were not 

based on a latent defect or affirmative misrepresentation did not “limit[] how 

Nalick may prove his omissions-based claims.” (Seagate I, supra, A158237.) 

Turning to materiality and knowledge, we concluded the record 

reflected a genuine issue of material fact regarding at what level AFRs 

become material and whether Seagate had exclusive knowledge of such 

AFRs. Central to that finding was our disagreement with the trial court’s 

interpretation of the declaration of Stefan Boedeker, which was submitted in 

support of Nalick’s opposition to Seagate’s motion for reconsideration of the

ruling denying summary judgment. 

Boedeker offered an opinion quantifying the economic loss for an AFR 

as low as 3 percent. The trial court interpreted Boedeker’s conclusion to be 

only AFRs at or above 3 percent are material. But Boedeker also analyzed 

AFRs “ ‘between 1% and 10% through interpolation.’ ” (Seagate I, supra, 

A158237.) Indeed, “Boedeker expressly stated ‘the model can be further 

refined to enable the quantification of economic losses for different interim 

AFRs,’ including ‘the specification of economic losses for all incremental AFRs 

between 1% and 50%.’ ” (Ibid.) Thus, the “court exceeded its role by adopting 

its own interpretation of Boedeker’s conclusions.” (Ibid.) We held that

“Boedeker’s declaration provides sufficient evidence of materiality for AFR’s 

above 1 percent to raise a genuine issue of material fact.” (Ibid.)

Finally, we determined the trial court’s “initial order” had correctly 

determined Seagate’s own evidence in support of its motion for summary 

adjudication raised a factual dispute regarding whether Seagate had 

knowledge of Drives with AFRs over 1 percent. (Seagate I, supra, A158237.) 
7

That evidence consisted of the declarations of David and Sek Nam “Allen” 

Ng, which discussed return rate information—not AFRs. Specifically, they 

“ ‘identif[ied] return rates [of Drives] that were in excess of 1% per year over 

the first two years, even, in Trane’s case, when “No Trouble Found” and 

“Could Not Duplicate” returns are excluded.’ ” (Seagate I, supra, A158237.) 

We held “ ‘a trier of fact presented with Seagate’s evidence [regarding return 

rates in excess of 1%] could conclude that at least some of the drive families 

at issue here had AFR’s in excess of 1% and that Seagate knew of those 

AFR’s as a result of return data.’ ” (Ibid.) Accordingly, the order granting 

summary adjudication was reversed.

C. Class Decertification

After the reversal of summary adjudication and remand, Seagate 

moved to decertify the class. Seagate raised several arguments in its 

decertification motion, three of which are relevant here: (1) “changed 

circumstances, theories of liability, and evidence warrant revisiting class 

certification”; (2) common questions do not predominate because Nalick could 

not provide common proof of the Drives’ AFRs; and (3) the certified class was 

not ascertainable. 

As a threshold matter, Seagate asserted changed circumstances

justified its request for decertification. First, Seagate argued Nalick’s theory 

of liability shifted from claiming a latent defect to an obligation to disclose an 

AFR above 1 percent. Second, in support of this “new theory of liability,” 

Seagate contended Nalick changed his evidence regarding AFRs. Third, 

Seagate alerted the court to a parallel action in the Northern District of 

California, where the federal court denied class certification based on the 

same products and theories of liability. Finally, Seagate claimed new case 
8

law required omissions-based claims to establish proof of class exposure to a 

partial representation to give rise to a duty to disclose.

On the merits of decertification, Seagate asserted individual questions 

predominate because the AFRs at issue vary. Specifically, there are different 

AFRs for the different products that use the Drives. Because Seagate’s 

ongoing reliability testing of the Drives was done on a rolling basis and fixes 

were implemented throughout the manufacturing process, Seagate asserted 

the AFRs of a single product would vary across testing cycles. Relatedly, 

Seagate argued two AFRs may not be equivalent because changes in 

manufacturing output affect the testing sample sizes and thus distort the 

AFR results. As to the federal case, Seagate underscored the federal court’s 

conclusion that “evidence of AFR rates for the drives at issue here is not 

common to the class” because of “ ‘the undisputed variance of [the AFR] 

metric across the class period.’ ” (Boldface omitted.)

Regarding ascertainability, Seagate argued the class was 

impermissibly overbroad. Specifically, Seagate noted the class definition 

“covers all consumers who purchased the [Drives] in California, regardless of 

the product, or the version of the product, over a period of over ten years, and 

regardless of whether the consumer actually saw or relied on any partial 

representation that gave rise to a duty to disclose a certain AFR rate” and 

regardless of whether they “experienced any drive failure or suffered any 

harm.” After separating out potential class members based on these 

differences, Seagate asserted there would be 72 subclasses. 

In opposition, Nalick countered that Seagate’s motion was untimely 

and not justified by “significant” changes in circumstances. Nalick stated his 

theory of liability had not changed, as evidenced by the fact the court certified 

a class based on omissions, not a latent defect theory. Further, the federal 
9

case Seagate relied on was decided nearly four years earlier—in July 2018—

and was not “new,” according to Nalick, because it merely applied settled law.

Nalick also claimed Seagate “present[ed] no new evidence” in support of

decertification.

Regarding predominance, Nalick argued Seagate “speculates that 

differences among the Drives’ versions might create individual issues” 

without submitting newly discovered evidence demonstrating that the Drives’ 

AFRs, or Seagate’s knowledge of them, actually varied over time. And, even 

assuming there was actual AFR variance, Nalick quoted the trial court’s 

original certification order stating the “reasonable consumer” test presents 

common questions despite Seagate’s evidence that “global failure rate for the 

Drives” may vary based on “their use.” To the extent return rates are not an 

accurate measure of the Drives’ AFRs, Nalick argued “that too is a common 

question.” 

In support of his opposition briefing, Nalick submitted the declaration 

of John Levy, Ph.D. Relying on the return data presented during summary 

adjudication proceedings, Levy declared “ ‘failure rates for each of the three 

Drive versions fell within a narrow range,’ ” which he concluded presents

common rather than individual issues. Citing Levy’s declaration, Nalick 

asserted, “Because the Drive only had three versions (Classic, BP, or BP2) 

and two uses (internal or external), a trial would involve, at most, the 

presentation of six failure rates.” 

Regarding ascertainability, Nalick argued the court should not revisit 

its prior decision because the parties stipulated the class definitions after 

class certification. He further contended the differences Seagate cited to 

defeat ascertainability were irrelevant. Specifically, he argued that Seagate’s 

representations were similar regardless of the product, that Levy concluded 
10

the AFRs “ ‘fell within a narrow range’ ” regardless of which Drive version 

was used in each product, and that absent class members do not need to 

demonstrate reliance. 

Following a hearing, the trial court decertified the class. The court 

concluded Seagate’s motion was procedurally proper because it was

“predicated on different arguments and evidence than its opposition to class

certification, which did not focus on AFRs.”4 The court also found the parallel 

federal case to be “new” because it was rendered postcertification. 

Turning to the merits, the court held individual questions predominate. 

The court observed that Nalick’s claims “rely on AFR to establish the 

predicate fact that the Drives had a high failure rate.” In accord with 

Seagate I, the court stated the predicate fact—i.e., the alleged AFRs—

“supports the element[] of materiality.” But Seagate’s evidence concerning

the AFRs demonstrated “different versions of the [Drives], rolling reliability 

testing, and fixes during the manufacturing process render the measure of 

AFR itself subject to individualized inquiries.” Further, whether AFRs were 

affected by mishandling “raise[d] individual inquiries into specific 

distribution channels, product placement at retailers, and whether a class 

member mishandled a Drive.” And, because “AFR variances are not 

necessarily applicable only to one set of class members,” the court “ ‘decline[d] 

to find [differences in the Drives’ AFRs were] a merits issue rather than a 

class certification issue.’ ” 

4 Later in its order, however, the court rejected the notion that Nalick’s 

theory of liability had changed. The court observed Nalick’s theory of liability 

was based on omissions of the Drives’ alleged high failure rates, and the fact 

that Nalick now identified AFRs above 1 percent as the failure rate a 

reasonable consumer would find material did not change his theory of 

liability. 
11

In reaching the conclusion that individual questions predominate—and 

relatedly that AFR variations present significant manageability concerns for 

trial—the court expressly cited and discussed the declarations of Greg 

Almgren, Karl Schweiss, and Harrie Netel.5 Almgren’s declaration described 

the reliability testing of the Drives and explained AFR may refer to different 

estimates during reliability testing. Further, Almgren stated the 

specifications for a Drive used in one product differed from the specifications 

used in other products. Schweiss’s declaration declared Seagate never 

specified AFRs for certain products and AFRs for different products were 

conditioned on different “power-on hours” per year depending on their 

anticipated uses. Netel’s declaration explained how measures of AFRs

during production actually varied by day and week due to the cycle of 

reliability testing, and he stated “ ‘the individual AFR for the 3TB drive, [] 

was not always considered to be as accurate because variances in 

manufacturing output resulted in variances of sample sizes each week.’ ” 

Netel further stated AFR testing measured the Drives’ reliability “ ‘before the 

products reach[ed] the hands of retailers and eventually, consumers.’ ” 

The trial court granted Seagate’s motion to strike Levy’s declaration on 

the grounds that its conclusions were speculative and not supported by 

evidence. The court observed Levy “did not offer any direct evidence of the 

Drives’ AFRs” and instead relied on return data. Thus, as the court 

explained, a critical assumption underlying Levy’s conclusion was that the 

Drives’ AFRs were “at least equal to” products’ return rates.

5 These declarations were submitted in support of Seagate’s March 

2022 “Motion to Decertify the Class, or in the Alternative, to Modify the Class 

Definition.” Almgren had also submitted a separate declaration in June 2017 

in support of Seagate’s opposition to Nalick’s motion for class certification.
12

Upon examining the return data on which Levy relied, the court 

concluded “that assumption [wa]s not supported.” The applicable return data 

came from the Trane declaration filed in support of Seagate’s motion for 

summary judgment. After adjusting for “ ‘no trouble found’ ” and “ ‘could not 

duplicate,’ ” Trane calculated a range of adjusted return rates for different 

versions of the Drives. Trane explained these adjusted return rates included 

returns due to mishandling. Because the data measured returns a year after

sale—in contrast to AFR’s measure of estimated failure rates before

distribution and sale—the court faulted Levy for failing to cite any studies or 

evidence establishing return rates correspond to “minimum” AFRs. 

Accordingly, the trial court determined Levy’s conclusion was unsound. The 

court therefore held that Nalick failed to meet his burden to show common 

proof of the AFRs. 

Independent of Nalick’s failure to establish common issues 

predominate, the court found Nalick did not meet his burden to show the 

existence of an ascertainable class. The court explained Nalick did not show 

how the class definition “could be narrowed to include only those class 

members who have viable claims.” In particular, the court highlighted that 

the class definition included consumers “whose drives had AFR rates of less 

than 1%, in addition to consumers whose mishandling or overuse of their 

drives caused their failure.” 

Thus, the trial court granted Seagate’s motion to decertify the class. 

Nalick appealed.
13

III.

DISCUSSION

A. Legal Standards

A trial court that discovers a class action is no longer proper retains 

flexibility to decertify the class. (Weinstat v. Dentsply lnternat., Inc. (2010) 

180 Cal.App.4th 1213, 1226 (Weinstat).) But decertification is appropriate 

“ ‘only where it is clear there exist changed circumstances making continued 

class action treatment improper.’ ” (Green v. Obledo (1981) 29 Cal.3d 126, 

148.) “A motion for decertification is not an opportunity for a disgruntled 

class defendant to seek a do-over of its previously unsuccessful opposition to 

certification.” (Williams v. Superior Court (2013) 221 Cal.App.4th 1353, 1360

(Williams).)

We review a decertification order for an abuse of discretion. (Moen v.

Regents of the University of California (2018) 25 Cal.App.5th 845, 853.) 

Unlike ordinary appellate review, however, “ ‘when denying class 

certification, the trial court must state its reasons, and we must review those 

reasons for correctness.’ ” (Peviani v. Arbors at California Oaks Property

Owner, LLC (2021) 62 Cal.App.5th 874, 887.) Accordingly, decertification 

resting on an invalid reason, such as improper legal criteria or an incorrect 

assumption, is an abuse of discretion. (Williams, supra, 221 Cal.App.4th at 

p. 1361.) Nevertheless, appellate review is “narrowly circumscribed,” 

reversing only for manifest abuse of discretion “ ‘ “[b]ecause trial courts are 

ideally situated to evaluate the efficiencies and practicalities of permitting 

group action.” ’ ” (Brinker Restaurant Corp. v. Superior Court (2012)

53 Cal.4th 1004, 1022 (Brinker).) 

The trial court’s predominance finding is reviewed for substantial 

evidence. (Lockheed Martin Corp. v. Superior Court (2003) 29 Cal.4th 1096, 
14

1106 (Lockheed).) The issue of predominance turns on “ ‘whether the theory 

of recovery advanced by the proponents of certification is, as an analytical 

matter, likely to prove amenable to class treatment.’ ” (Brinker, supra,

53 Cal.4th at p. 1021.) “ ‘Reviewing courts consistently look to the allegations 

of the complaint and the declarations of attorneys representing the plaintiff 

class to resolve this question.’ ” (Sav-On Drug Stores, Inc. v. Superior Court

(2004) 34 Cal.4th 319, 327 (Sav-On).) On review for substantial evidence, 

appellate courts view the record in the light most favorable to the respondent 

and resolve all evidentiary conflicts and indulge all reasonable inferences in 

favor of the judgment. (Williams-Sonoma Song-Beverly Act Cases (2019) 

40 Cal.App.5th 647, 650.)

Evidence Code section 802 permits the court in its discretion to exclude 

expert testimony on the grounds that there is no reasonable basis for the 

opinion. (See Sargon Enterprises, Inc. v. University of Southern California

(2012) 55 Cal.4th 747, 771 (Sargon).) We review the exclusion of expert 

testimony for abuse of discretion. (Id. at p. 773.)

B. New Evidence Justified Revisiting Certification

While a class “can be decertified at any time, even during trial, should 

it later appear individual issues dominate the case” (Macmanus v. A. E.

Realty Partners (1987) 195 Cal.App.3d 1106, 1117), decertification “ ‘typically 

occur[s] in response to a significant change in circumstances’ ” (Williams, 

supra, 221 Cal.App.4th at p. 1360). And the party seeking decertification 

“generally has the burden to show that certification is no longer warranted.” 

(Kight v. CashCall, Inc. (2014) 231 Cal.App.4th 112, 126.) Thus, to allow

courts the flexibility to decertify in the face of changed circumstances while 

curtailing abuse by class defendants, a class defendant is required to show 

new evidence or new law demonstrating such changed circumstances. 

(Weinstat, supra, 180 Cal.App.4th at p. 1226.)
15

The trial court articulated Seagate’s motion was proper because it was 

“predicated on different arguments and evidence than its opposition to class 

certification, which did not focus on AFRs.” Specifically, Seagate proffered

the declarations of Almgren, Schweiss, and Netel, which all address how 

AFRs are calculated. Nalick counters that none of this “new” evidence was

“newly discovered” after the initial class certification order. (Cf. Weinstat,

supra, 180 Cal.App.4th at p. 1225 [decertification improper where evidence is 

“newly packaged, but not newly discovered”].)

Nalick’s assertion is misleading and ignores the new evidence that he 

produced after class certification in opposition to Seagate’s motion for 

summary judgment. As the decertification order explained, the initial class 

certification proceedings did not focus on AFRs.6 Instead, Nalick’s alleged 

common proof of the Drives’ “abnormally high failure rate” was a study 

purporting the Drives’ failure rate was 78% and a recall of OEM products due 

to postsale returns. Seagate’s opposition was responsive—and naturally 

limited in its response—to the asserted common proof.

7 Thus, neither party’s 

initial class certification briefing addressed how AFRs are measured or 

whether calculating AFRs for products across the class period would require 

individualized inquiries.

Despite noting the absence of evidence regarding the failure rate, the

trial court determined the “failure rate of a consumer hard drive” existed “by 

definition” and thus was susceptible to common proof. It granted class 

6 The only reference to the Drives’ AFRs in Nalick’s motion was an 

assertion that Seagate “published and disseminated detailed reliability and 

data specifications for the Drives, claiming that the ST3000DM001’s 

annualized failure rate (‘AFR’) was less than 1%.” 

7 Seagate did argue that evidence of misuse by certain class members 

raised individual issues for its affirmative defense. 
16

certification on certain CLRA and UCL claims based on alleged omissions 

because Nalick “may be able to demonstrate that whatever the failure rate 

was—and, by definition, there was some failure rate, there always is—it was 

sufficiently high that consumers should have been alerted to it.” In other 

words, to succeed at trial, Nalick would need to present evidence of the actual 

AFRs.

Accordingly, in opposition to Seagate’s motion for summary 

adjudication, Nalick submitted new evidence regarding the Drives’ AFRs. At 

this stage, such a showing was necessary because his claims “rely on AFR to 

establish the predicate fact that the Drives had a high failure rate” across the 

class. And while Nalick’s theory of liability did not change, his evidence and 

arguments in support of that theory did. Indeed, it was not until after class 

certification was granted, during summary adjudication proceedings, when

Nalick identified evidence that a particular failure rate—1 percent—was 

material to a reasonable consumer. Tellingly, in its initial order denying 

Seagate’s motion for summary adjudication, the trial court noted 

decertification may be appropriate if evidence regarding the “exact failure 

rate” showed AFRs varied. This was prescient.

After this court reversed the trial court’s subsequent order granting 

summary adjudication, Seagate moved to decertify the class and submitted 

additional evidence in support of its motion. Seagate’s newly submitted

evidence showed—for the first time—the variability of Drives’ AFRs across 

both products and the class period. This was “new” evidence regarding 

common proof of the AFRs, not previously considered by the court, and arose 

in response to Nalick’s postcertification evidence and arguments regarding 

the materiality of an AFR at or above 1 percent.
17

Nalick’s cited authorities do not stand for the proposition that changed 

circumstances may only be demonstrated by newly arisen facts. In Williams, 

the decertification order relied on evidence from a declaration “filed in 

support of petitioner’s motion for certification.” (Williams, supra, 

221 Cal.App.4th at p. 1368.) Because the same evidence had been presented 

in support of the original motion for class certification, it was demonstrably

not new. Weinstat is similarly inapposite. There, the trial court decertified

two claims based on allegedly new law, not new evidence. (Weinstat, supra, 

180 Cal.App.4th at pp. 1217–1218.)8 The court decertified a UCL claim based 

on an incorrect interpretation of new case law, then decertified a breach of 

warranty claim on the same basis despite the changed “circumstance only 

pertain[ing] to the UCL cause of action.” (Weinstat, at pp. 1224, 1226.) The 

appellate court criticized the rulings as “in effect reassess[ing] the matter 

under existing law, coupled with newly packaged, but not newly discovered, 

evidence.” (Id. at p. 1225.) Weinstat did not establish a rule restricting new 

evidence to newly arisen facts.

Nalick also cites People v. Anderson (2008) 169 Cal.App.4th 321, which

accords with our analysis. There, the court denied a motion to suppress and 

that ruling was upheld in the first appeal, which reversed the defendant’s 

conviction on other grounds. (Id. at p. 325.) On remand, the defendant 

renewed the motion, and the court conducted a new hearing and considered 

new evidence without reconsidering evidence submitted at the first hearing. 

(Id. at p. 329.) On appeal the second time, the appellate court condoned this 

approach and articulated a framework for determining when a court must 

8 Indeed, the defendant in Weinstat did not contend there was new 

evidence, instead expressly arguing “there is no requirement of changed 

circumstances or new evidence” to revisit certification. (Weinstat, supra, 

180 Cal.App.4th at p. 1226.) 
18

redetermine evidentiary matters on remand where the underlying issue was 

“actually addressed by the [first] appellate court.” (Id. at pp. 332–333.) First, 

the court must “determine whether the renewed motion involves ‘new or 

different’ evidence. If not, the trial court must follow the ruling of the 

appellate court; if so, the trial court must redetermine the suppression 

motion.” (Id. at p. 333.) The Anderson court explained “new or different” 

evidence in such a context included evidence presented on remand that

“raise[s] material factual or legal issues not considered by the original trial

judge.” (Id. at pp. 333–334, italics omitted.) Under this standard, Nalick and

Seagate presented new evidence—i.e., evidence not considered by the court at

the initial class certification proceedings.

Further, the reversal of the trial court’s grant of summary adjudication 

in Seagate I did not preclude decertification because the issue of common 

proof was not “actually addressed.” Under the law of the case doctrine, “[t]he 

decision of an appellate court, stating a rule of law necessary to the decision 

of the case, conclusively establishes that rule and makes it determinative of 

the rights of the same parties in any subsequent retrial or appeal in the same 

case.” (Morohoshi v. Pacific Home (2004) 34 Cal.4th 482, 491.) In Seagate I, 

we found the Boedeker declaration was “sufficient evidence of materiality for 

AFR’s above 1 percent to raise a genuine issue of material fact.” (Seagate I,

supra, A158237.) We also found—based on the Trane and Ng declarations 

submitted in support of Seagate’s motion for summary adjudication—a trier 

of fact “could conclude that at least some of the drive families at issue here 

had AFR’s in excess of 1% and that Seagate knew of those AFR’s as a result 

of return data.” (Ibid., italics added.) We did not, however, hold that the 

Boedeker declaration or return rates to which Trane and Ng testified were 

common proof of a 1 percent AFR across the different Drive versions or across 
19

the entire class. We did not expressly or implicitly decide whether common 

issues predominate or whether the factual inquiries into AFRs were

manageable. (See Searle v. Allstate Life Ins. Co. (1985) 38 Cal.3d 425, 435 

[explaining justification “for the [law of the case doctrine] is inoperative when 

the court hearing the subsequent appeal determines that there should be a 

reversal on a ground that was not considered on the prior appeal”].) 

Nalick’s authorities are unavailing for the same reason. For example, 

the cross-defendant in Nissan Motor Acceptance Cases (2021) 63 Cal.App.5th 

793 “contend[ed] no evidence showed” justifiable reliance, but the appellate 

court rejected the same argument in an earlier appeal. (Id. at pp. 823, 824.) 

Because the cross-complainant presented the same evidence regarding the 

same issue—i.e., sufficiency of the evidence of justifiable reliance—the law of 

the case doctrine precluded a different result. (Id. at p. 824.) Moreover, the 

court expressly stated the law of the case doctrine was inapplicable to a 

separate challenge by the cross-defendant. (See id. at pp. 824–825 [reviewing 

whether there was substantial evidence of negligent representation because

the first appeal “did not expressly or implicitly decide” the issue].)9 The same 

logic holds here. Because common proof was not expressly or implicitly

decided in Seagate I, the court’s subsequent ruling that individualized issues 

predominate the inquiry into AFRs did not contravene the law of the case.

In sum, the evidence submitted postcertification regarding the Drives’ 

actual AFRs demonstrated changed circumstances. Namely, that the 

predicate fact of Nalick’s claims was susceptible to individualized inquiries 

9 McCoy v. Hearst Corp. (1991) 227 Cal.App.3d 1657, 1661–1662, and 

Gibson v. State (1962) 208 Cal.App.2d 458, 461–462 are likewise inapposite. 

Both involved retrials after appellate rulings on the sufficiency of the 

evidence introduced at trial. Here, the issue is not the sufficiency of the 

evidence; it is whether there is common proof of the AFRs.
20

and manageability concerns. The court therefore did not abuse its discretion 

by considering Seagate’s request for decertification.

10

C. The Court Did Not Impermissibly Resolve Merits Questions

A trial court’s inquiry into whether certification is proper is essentially 

procedural, and the “resolution of disputes over the merits of a case generally 

must be postponed until after class certification has been decided.” (Brinker,

supra, 53 Cal.4th at p. 1023.) So the court “ordinarily must assume the 

claims have merit.” (Williams, supra, 221 Cal.App.4th at p. 1360.) But “no 

such assumption applies to the issues in dispute on [a certification] motion,” 

including predominance. (Apple Inc. v. Superior Court (2018) 19 Cal.App.5th 

1101, 1119, fn. 3.)

Issues related to predominance often overlap issues affecting the merits 

of a case. (Brinker, supra, 53 Cal.4th at pp. 1023–1024.) To decide whether

individual or common issues predominate, the “court must examine the

plaintiff’s theory of recovery, assess the nature of the legal and factual 

disputes likely to be presented,” and, if necessary, resolve disputed threshold 

legal or factual questions. (Id. at p. 1025; see also Sav-On, supra, 34 Cal.4th 

at p. 334 [“Predominance is a comparative concept”].) “ ‘Critically, if the 

parties’ evidence is conflicting on the issue of whether common or individual 

questions predominate (as it often is . . . ), the trial court is permitted to 

credit one party’s evidence over the other’s in determining whether the 

10 Nalick also argues the court was wrong in finding a similar federal 

action was “new law” merely because it was rendered post-certification. We 

assume without deciding that Nalick is correct. (See Ovitz v. Schulman

(2005) 133 Cal.App.4th 830, 848.) Decertification resting on an invalid 

reason is an abuse of discretion. (Williams, supra, 221 Cal.App.4th at 

p. 1361.) But, because the court expressly stated new evidence was an 

independent—and the primary—premise for considering decertification, this 

error is insufficient to reverse.
21

requirements for class certification have been met.’ ” (Mies v. Sephora

U.S.A., Inc. (2015) 234 Cal.App.4th 967, 981 (Mies).)

Nalick argues the court impermissibly resolved merits questions by 

“reject[ing] a fundamental leg of Nalick’s theory of liability—that Seagate’s 

own internal return data provided critical, classwide evidence of the Drives’ 

common failure rates.” Not so. The predicate factual issue raised by Nalick’s 

theory of recovery was that the Drives’ AFR exceeds 1 percent. If Drives’ 

AFRs vary—including between different Drive versions and products and due 

to rolling fixes and testing cycles—then liability is susceptible to 

individualized inquiries. Therefore, the variability of AFRs is an issue of 

predominance that may be considered. 

As discussed below, Seagate presented substantial evidence showing 

the AFRs vary due to several factors, which presents “serious manageability 

concerns for trial.” The court then assessed whether Nalick met his burden 

of showing common issues predominate or that it “ ‘will be feasible to try the 

case as a class action.’ ” It found he did not.11 

Undertaking this balancing analysis was appropriate and did not 

improperly resolve merits questions. (See Mies, supra, 234 Cal.App.4th at 

p. 983.) Accordingly, we review the court’s finding that individualized issues 

predominate for substantial evidence. (Lockheed, supra, 29 Cal.4th at 

p. 1106.) 

D. Substantial Evidence Supports Predominance Finding

1. Seagate Evidence 

11 As explained above, while the law of the case holds the return data is 

sufficient for a trier of fact to conclude “at least some of the drive families” 

had AFRs greater than 1 percent, it does not hold the return data is common 

proof of the AFRs class-wide. (See Seagate I, supra, A158237.) 
22

Predominance turns on “whether the theory of recovery advanced by 

the proponents of certification is, as an analytical matter, likely to prove 

amenable to class treatment.” (Sav-On, supra, 34 Cal.4th at p. 327.)

Accordingly, the trial court correctly observed Nalick’s claims “rely on AFR to 

establish the predicate fact that the Drives had a high failure rate.” The 

court then evaluated the evidence submitted in support of Seagate’s 

decertification motion—primarily, the declarations of Almgren and Netel. 

The court concluded “the different versions of the Grenada drives, rolling 

reliability testing, and fixes during the manufacturing process render the 

measure of AFR itself subject to individual inquiries.” Viewing the record in 

the light most favorable to Seagate and indulging all reasonable inferences in 

favor of the judgment, we affirm. (See Williams-Sonoma Song-Beverly Act

Cases, supra, 40 Cal.App.5th at p. 650.) 

This conclusion was grounded in substantial evidence. The court’s 

decertification order relied on Almgren’s declaration describing “significant 

changes” between different versions of the Drives, which required different 

reliability demonstration testing, which in turn affected AFRs. Reliability 

demonstration testing “included calculating the mean time between/before 

failure (‘MTBF’) as well as AFRs.” But “AFR” may refer to different 

estimates—“ ‘raw’ AFR” reflected estimates before fixes were implemented,

while “ ‘demonstrated reduced AFR’ ” reflected AFR after fixes were 

implemented. Moreover, the AFRs of different versions of the Drives were 

not necessarily equivalent because the projected AFR of any given version 

was impacted by the estimated power-on hours of that version’s intended use. 

For example, an internal hard drive was expected to be used approximately 

40 hours a week, while an external hard drive was expected to be used less 

than half as much. Indeed, some versions of the Drives did not have an AFR 
23

target at all. Such Drives instead had to meet an MTBF specification of 

100,000 hours, which corresponds to an AFR around 1 percent. However,

that equivalence depends on an assumption that the product will be used for 

less than 100 power-on hours. 

Further evidence the court cited was Netel’s declaration regarding 

Seagate’s ongoing reliability testing, which occurred “post launch of a 

product” and assessed the Drives “on a rolling basis with a new sample pulled 

for testing each week.” “Typical testing [of hard drives sold as internal 

desktop drives] takes six weeks, so daily or weekly results are assessed on 

the entire group of drives, which is a rolling group of drives that has been in 

testing for various lengths of time.” Ongoing reliability testing produced two 

different calculations of “AFR”: (1) “the average AFR” across hard drives; 

and, (2) “the individual AFR for the 3 TB drive, which was not always 

considered to be as accurate because variances in manufacturing output 

resulted in variances of sample sizes each week.” Seagate also monitored a 

third metric—“ ‘rolling AFR’ ”—an average of AFRs for a six-week period. 

The court also credited Netel’s declaration that Seagate implemented

engineering change requests to improve the Drives throughout 

manufacturing: “ ‘Although often minor, it cannot be stated that a drive from 

the first week of manufacture is the exact same as a drive from the final week 

of manufacture.’ ” Moreover, if an ongoing reliability testing result—i.e., an 

MTBF or AFR calculation—exceeded a certain threshold, then Seagate would 

issue a “ship hold” and implement a fix. Thus, “ ‘the reported AFR in 

documents could be higher than the actual AFR of drives shipped to 

consumers for two reasons: (1) the reported AFR is the AFR that triggered 

the ship hold . . . ; (2) even after a fix was implemented, it could take time for 
24

the fixed drives to make their way into testing and bring down the “raw” AFR 

to match the AFR of drives being shipped to consumers.’ ”

This evidence adequately substantiated Seagate’s contention that

individual issues predominate and present manageability issues.

12 The court 

then assessed Nalick’s countervailing evidence to determine if he met his 

burden of showing that common issues predominate or that it “will be 

feasible to try the case as a class action.” (Duran v. U.S. Bank National Assn.

(2014) 59 Cal.4th 1, 27.) After evaluating and excluding Nalick’s expert

testimony, it determined he did not. (See Sav-On, supra, 34 Cal.4th at p. 334 

[“Predominance is a comparative concept”].)

2. Court Properly Excluded Nalick’s Predominance Evidence

Trial courts have discretion to exclude expert testimony on the grounds

that there is no reasonable basis for the opinion. (See Sargon, supra, 

55 Cal.4th at p. 771.) A court’s inquiry into “whether expert opinion is 

founded on sound logic is not a decision on its persuasiveness.” (Id. at 

p. 772.) The court merely determines “whether the matter relied on can 

provide a reasonable basis for the opinion or whether that opinion is based on 

a leap of logic or conjecture.” (Ibid.) Thus, the issue before us is whether the 

court abused its discretion in excluding Levy’s testimony, not whether there 

is common proof of the AFRs. (Id. at p. 773.) But how AFRs are calculated is 

12 As the trial court recognized, the federal court reached the same 

conclusion. It found the differences among the Drives, and the different 

reliability demonstration testing standards applied to the internal and 

external drives, weighed against commonality. (See In re Seagate Technology 

LLC Litigation (2018) 326 F.R.D. 223, 244.) This reinforces our view that 

substantial evidence supports the court’s determination. (See also Brinker,

supra, 53 Cal.4th at p. 1022 [trial courts are ideally situated to evaluate the 

efficiencies and practicalities of permitting group action].)
25

relevant to help define the type of matter on which an expert may reasonably 

rely in reaching such a conclusion. (See id. at pp. 775–776.)

Nalick’s asserted common proof of the Drives’ AFRs was limited to the 

Levy declaration, which relied on the Trane and Ng declarations regarding 

return rates. As the court’s decertification order describes, Levy opined the 

Drives’ return rates “ ‘establish a lower bound for the actual failure rates’ ”—

i.e., a minimum AFR—and “ ‘the failure rates for each of the three Drive 

versions fell within a narrow range.’ ” The court was not persuaded. It 

concluded Levy’s opinion was speculative and unreliable because he 

“conflate[d] the two measures,” return rates and AFRs, “without any showing 

as to the relationship between them.” 

This conclusion does not contravene the law of the case. As discussed 

above, in Seagate I we determined a trier of fact presented with the same 

return rate data could conclude AFRs of “at least some of the drive families”

exceeded 1 percent. (Seagate I, supra, A158237, italics added.) We did not 

rule such return data was common proof of the AFRs of all versions of the 

Drives across the class period. Nor did we determine such return data was a 

reasonable basis for establishing the Drives’ “minimum AFRs.” As the trial 

court explained, “[t]hat Seagate may have been put on notice by high return 

rates of the possibility of higher than usual AFRs does not establish that the 

two are interchangeable.” In other words, while sufficient to create a triable 

issue of material fact as to the Drives’ AFRs and Seagate’s knowledge of high 

failure rates, it was proper for the court to analyze whether the return data 

was a reasonable basis for Levy to opine “ ‘the failure rates for each of the 

three Drive versions fell within a narrow range’ ” and all correlate with the 

“minimum AFR.” 
26

Levy asserted the return rate data could be used to establish the 

“minimum AFRs” because “ ‘[c]ommon sense suggests that many consumers 

will not return a failing device.’ ” But the court observed several flaws in 

using the return data as common proof of AFRs across the class period. To 

start, Nalick argued at summary judgment that Trane’s declaration “ ‘does 

not dispositively resolve the question of what the Drives’ AFRs actually 

were.’ ” And the court observed Ng’s declaration “relate[d] to OEM products 

that are outside the class definition in this case,” which Nalick acknowledges.

Further, while Levy admitted the return rates were measured 12 and 24 

months after sale and AFR measures the projected failure rate before sale, 

Levy did “not cite any studies or other evidence showing a correlation

between the two or supporting his critical assumption that there is such a 

correlation.” 

Further undermining any correlation between return rates and AFRs—

and showcasing the speculative nature of his conclusions—was Levy’s 

suggestion that Seagate’s AFR metrics may be artificially low. Levy 

surmised “ ‘the fact that the manufacturer . . . could not confirm that a hard 

drive failed or did not reproduce the failure in its testing does not necessarily 

mean that the Drive did not fail.’ ” The court was unimpressed that “without 

evidence” Levy “assume[d]” the “Drives’ failure rate must have been higher 

than [Seagate’s] own testing established.” 

The court also criticized Levy’s declaration for inadequately addressing 

how return data was common proof of different Drive versions’ AFRs. For 

example, Trane declared the return data encompassed mishandled 

products—an issue susceptible to individualized inquiries. Also, Levy opined

the “minimum AFR”—i.e., the adjusted return rates—for three of the Drive 

versions ranged from 0.92 percent to 1.99 percent. In other words, at least 
27

one version did not have an adjusted return rate above 1 percent. But Levy 

stated—without any supporting evidence—that this version “likely” had an 

AFR exceeding 1 percent because “ ‘some consumers may not return failing 

drives.’ ” Moreover, this range of adjusted return rates only reflected “return 

data for [Seagate’s] internal Drives.” And despite admitting he “did not

break out the return rates for [Seagate’s] external products by Drive version,” 

Levy stated “without explanation” that “those drives, too, had a minimum 

AFR of 2.22%.” 

The trial court did not abuse its discretion by excluding Levy’s

testimony. It properly found his conclusions were too speculative to show 

common proof of AFRs. 

Accordingly, the court held Nalick failed to meet his burden to show 

that common issues predominate over individualized issues, or that it “will be 

feasible to try the case as a class action.” (Duran v. U.S. Bank National 

Assn., supra, 59 Cal.4th at p. 27.) Finding substantial evidence in support of 

this holding, we affirm.

3. Ascertainability

Nalick also argues the trial court erred in holding the class was not 

ascertainable by applying improper criteria and assumptions. We need not 

reach this issue, because we have determined the court did not abuse its 

discretion in finding common issues no longer predominated, warranting 

decertification of the class. (See Kight v. CashCall, Inc., supra,

231 Cal.App.4th at p. 128 [predominance sufficient ground for 

decertification].)
28

IV.

DISPOSITION

The order is affirmed. Seagate is entitled to costs on appeal. (Cal. 

Rules of Court, rule 8.278(a)(2).)
29

CASTRO, J.*

WE CONCUR:

HUMES, P. J.

LANGHORNE WILSON, J.

A166356

Nalick v. Seagate Technology LLC

* Judge of the Alameda County Superior Court, assigned by the Chief 

Justice pursuant to article VI, section 6 of the California Constitution.