DENY; and Opinion Filed February 1, 2019.

In The

Court of Appeals

Fifth District of Texas at Dallas

No. 05-19-00035-CV

IN RE PATRICIA KENNEDY, Relator

Original Proceeding from the 44th Judicial District Court

Dallas County, Texas

Trial Court Cause No. DC-16-15332

MEMORANDUM OPINION

Before Justices Brown, Schenck, and Reichek

Opinion by Justice Schenck

The underlying proceeding is a personal injury suit arising from a slip and fall at a fast food 

restaurant. Trial is set for February 4, 2019. In this original proceeding, relator complains of an 

October 17, 2018 order striking her June 8, 2018 supplemental expert designations. 

Mandamus will issue only to correct a clear abuse of discretion for which relator has no 

adequate remedy at law. In re Prudential Ins. Co. of Am., 148 S.W.3d 124, 135 (Tex. 2004) (orig.

proceeding); Walker v. Packer, 827 S.W.2d 833, 839-40 (Tex. 1992) (orig. proceeding). A trial 

court abuses its discretion when it acts in an unreasonable or arbitrary manner or, stated differently, 

when it acts without reference to guiding rules and principles. City of San Benito v. Rio Grande 

Valley Gas Co., 109 S.W.3d 750, 757 (Tex. 2003). An appellate remedy is adequate when any 

benefits to mandamus review are outweighed by the detriments; on the other hand, when the 

benefits outweigh the detriments, appellate courts must consider whether the appellate remedy is 

adequate. In re Prudential Ins. Co., 148 S.W.3d at 136. “Whether a trial court abused its discretion 
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in excluding evidence because it was untimely disclosed is generally reviewable on appeal from 

the final judgment.” In re Tyson Foods, Inc., No. 12-17-00156-CV, 2017 WL 3225051, at *2 (Tex. 

App.—Tyler July 31, 2017, orig. proceeding) (mem. op.) (citing Beinar v. Deegan, 432 S.W.3d 

398, 406 (Tex. App.—Dallas 2014, no pet.) (review of exclusion of untimely disclosed evidence 

following summary judgment); Tranum v. Broadway, 283 S.W.3d 403, 425–26 (Tex. App.–Waco 

2008, pet. denied) (review of exclusion of expert testimony under Rule 193.6 reviewed on appeal)). 

A party does not have an adequate remedy by appeal, however, when the party’s ability to present 

a viable claim or defense is severely compromised or vitiated by the erroneous discovery ruling to 

the extent that it is effectively denied the ability to develop the merits of its case. Walker, 827 

S.W.2d at 843.

Although mandamus is not an equitable remedy, its issuance is largely controlled by 

equitable principles. Rivercenter Assocs. v. Rivera, 858 S.W.2d 366, 367 (Tex. 1993) (orig. 

proceeding). One such principle is that “equity aids the diligent and not those who slumber on their 

rights.” Id. Thus, delaying the filing of a petition for mandamus relief may waive the right to 

mandamus unless the relator can justify the delay. In re Int’l Profit Assocs., Inc., 274 S.W.3d 672, 

676 (Tex. 2009) (orig. proceeding); see also In re Pendragon Transp. LLC, 423 S.W.3d 537, 540 

(Tex. App.—Dallas 2014, orig. proceeding) (laches applied and petition filed less than two weeks 

before trial and six months after order issued); Bailey v. Baker, 696 S.W.2d 255, 256 (Tex. App.—

Houston [14th Dist.] 1985, orig. proceeding) (four-month delay, no explanation for delay, and filed

two weeks prior to trial).

Based on the record before us, we conclude relator has not shown she is entitled to the 

relief requested because relator has not established the trial court abused its discretion, has not 

shown she lacks an adequate remedy on appeal, and has not explained her delay in seeking 

mandamus relief. Accordingly, we deny relator’s petition for writ of mandamus. See TEX. R. APP.
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P. 52.8(a) (the court must deny the petition if the court determines relator is not entitled to the 

relief sought).

190035F.P05

/David J. Schenck/

DAVID J. SCHENCK

JUSTICE