did not exercise diligence in seeking leave and we think the court abuses discretion in reaching that conclusion largely because of apple's discovery mini misconduct  fact that apple concealed from d s s for five years and in fact there was a specific contention in raw dettori served on apple that asked to state all factual and legal grounds for its denial that it infringed any of the asserted patents and apple provided us with an incomplete and misleading answer to that in iraq tory thinking this very information and the district court essentially gave no substracting mode there is an enjoyment that we're disclose into india picks and the difference between the two is not relevant to the issues of infringement or validity in this case so  as you know we're in appellate court here and i guess it's unclear to me how can we conclude that apple's behavior here rose to the level of discovery misconduct when  the court below never made such a finding and you never filed a motion seeking to sanction apple for any kind of discovery misconduct so how are we at this stage given the posture of the case able to so easily conclude such a thing and thereby overturn the district court's decision here when we certainly argued in court below that apple's discovery misconduct was what lulled d s s to sleep if you will and to and to not appreciate that apple will use this broad opposing party would under some circumstances justify delay so therefore there was no point in filing a motion to compel because it wasn't as if they didn't answer they gave a misleading in completing answer and only apple knew that it was misleading and then complete because what was it about their answer that was misleading as i understood it they offered a blanket denial of infringing any relevant claim and there was a delay that was the result of it's all misconduct in giving incomplete and misleading answer it would have been very easy to say hey you should dismiss this case because we don't use efforts to find out exactly what was the mode used in the apple products that accounted for the little low duty cycle and the regular cycle for communicating between the peripherals and the computing device and so this court does have the power to take a look at the record and see that the five year delay absence of stays was due entirely to the fact that apple hit the following up with what judge chan called the story you're telling is you know is one that the district court live i mean district courts in our system manage all these discovery disputes and follow the case i mean i have a timeline in my bench book here and it spans years and years and various exchanges and do appreciate that it's difficult for us at the appellate level t dislodge the judge's conclusions when he's lived with this case from day to day and you could have come to him if there were a problem with discovery presumably all of these concealment issues were raised with him he was there at the time to assess the validity of those and it's just really difficult at the appellate level for us to nd guess under a very deferential standard of review the district courts you know judgments about these matters where i do i do appreciate that as a public courts do not like to because they're not really assigned the duty of engaging in that kind of as you call it nd guessing but that's not what's going on here i mean what happens is on paper it's in the record so there's no credibility issues or other kind of you had to be there type of an issue or for you to determine was there delay and who's responsible for it the fact the undisputed fact is that apple did not disclose these highly important facts for five years even though it had a duty to do so and its failure to disclose and it didn't use bt to sniff some rating and then it didn't stead use the brock town proprietary mode that is undisputed it didn't disclose that it was five years and then they finally disclosed it virtually right before there just to get some clarification here i mean isn't there doesn't part of the duty following you as the as the party with the burden of proof in this matter to follow up with the opposing party to  ferret out just exactly how their products are operating and whether or not your initial theory of how their products operate line up with your claim limitations to think that  actually if you get this kind of blanket the nile then it seems it stands to reason that then the the next move is on you to chase after them a little bit to try to nail down om to get to the bottom of things it was not on notice an investigation notice if you will of anything from apple that would lead d s s to believe that apple did not use bluetooth  or that it did use a rd party suppliers mode of wireless communication so we did ask the discovery we did get answers but there was nothing to indicate to us that we were wrong about that i mean it would have been evident to me i think that district court kind of covered that right didn't he determine that the source code another documents apple produced in two thousand and fourteen should have clued you in to the fact that they used the broadcast proprietary mode or me that they didn't use the bluetooth up well that just that i think given that there was an optional if they feature you should have been on high alert confirm that apple actually uses act so i don't know what your argument he dealt with that and i'm having a little bit of a hard time saying that we can conclude that he abused his discretion with his do not support it and all the notion that the met one file in the one folder in source code made a vague reference to a and i can't use the phrase because it's confidential but the  in the device that didn't tell us about what mode was being used and wasn't sub rating bluetooth but it was the broadcom method and then they also argue in their briefs which the court can find that you could have tested the devices that s failed to show did cause to add its new broadcom proprietary mode infringement theory after fact discovery closed the dish a court properly identified numerous reasons why d s s should have acted sooner to formulate this theory it's finding that d f s failed to show diligence was not an abuse of discretion the court also properly found prejudice to apple and this is another independent grounds for affirming on this issue the nd year honors recently found that sniff mode one point only was a new infringement theory that d s s raised for the st time far too late in the case in may two thousand and fourteen d s s served amended infringement contentions based it seems to me that you knew all along that you didn't use bluetooth yet separate it's trading mellowed right you know that a lot of your honor the record does not indicate that and part of the reason why the record does not indicate the state of apple's knowledge on that subject is because the district court found the s s never pressed apple for more detailed responses to contention in iraq a tory number one on using your honor the record simply doesn't enable me to provide an answer to that question because all we know is that in its st supplemental on the why why do we need the record to tell us i mean you're representing apple your apple so therefore you know why you could comfortably claim on behalf of your client that you did infringe this limitation so i mean i'd appreciate if you didn't hide behind that the cold record this thing that sitting in a courtroom doc it somewhere is is doesn't reveal the answer you know the answers to what was the answer for why you answered the way you answered when you said you don't  s we do not practice these limitations including we do not practice the code sequence limitation from that point onward d s s never complained that it needed a more detailed response to that contention in iraq a story that response was not incorrect and it was not incomplete and apple never changed its position that it did not pr those limitations the s s showed consistently throughout the case that it knew how to complain about discovery issues as one of many examples on november th two thousand and eighteen at appendix pages tory in that letter or in any of its other many discovery letters during that time apple did later on supplement it in iraq a tory responses with additional information that apple learned and your honor there's simply no evidence in the record of any discovery misconduct or hiding the ball there is no finding of that from the district court there is no record of that from the district court and your honor i do not have the personal knowledge to narrate why apple respond two discovery request and took certain actions or didn't take certain actions in discovery along the way of the five plus years of this case and moreover the district court was the place for d s s to raise and litigate these issues if it had any concerns about the level of detail that was provided in apple's june th two thousand and fourteen discovery responses your honour's the elephant in the room that d s s tries to ignore is the fact that they accused an optional feature of the bluetooth standard and therefore as the district court reasonably found d s s should have been on high alert from even before it filed this lawsuit complained about the level of detail in apple's contention in iraq a tory response is that issue could have been fully vetted at the district court level we told the s s that we do not infringe and that we do not practice the code sequence limitation all the way back to june two thousand and fourteen when you look at what d s s did during that time it chose to backload discovery and were pointed out the s s could have done many many things to surface these issues earlier and to force apple to do certain things that that perhaps may have led to some earlier supplementation for example in addition to pressing the issue if it had been dissatisfied with the level of detail in the contention rog responses the district court said that d s s could have followed with specific technical request they could have served an r s a saying apple were accusing you of using an optional feature of the bluetooth standard do you use that optional feature they right your honor it was in mr giles is deposition that he testified that apple's products do not use sniff stub rating however your honor that was not an instance of a cat being files for these peripherals we tested the apple p ninety one mouse in q six keyboard based on samples we had obtained and they determined allegedly the modes that were used and they also  apple did not use snus sub braiding to mantes as they said in their may two thousand and fourteen amended infringement contentions that that was not information that was uniquely in the possession of anyone pressed again just your honor as you mentioned i think at the outset of your argument correctly the district court had two bases and one was that it would be prejudicial to apple so how would this have been prejudicial to apple i mean it very very late in the case and fact discovery had been completed plain construction had being completed and even though with respect to the broadcom proprietary mode theory the district court didn't find that there were  specific arguments that apple would having and could have made the district court was within his discretion to say it is prejudicial when you're trying to completely change your infringement theory so late in the case and this court in cases like cruz and real time data has a firm findings of prejudice without requiring specific arguments that otherwise would have been made your honor if i if i may conclude on one point unless the court has further questions it is again significant here that broadcom was the supplier of the accused chips here and the district court also focused on that issue in addition to the optional nature of the feature of the blue standard that d s s was accusing as another reason why d s s lacked diligence again the court has has focused on apple's discovery responses and apple again reiterates that there was no evidence no finding and no record of discovery misconduct there was also another place that d s s should have gone to look supplied the accused chips for at least some portion of the apple products that they were accusing and also your honor at page fifty six dollars of d s s is opening brief the d that the fact that the accused devices used a broadcom chip quote was easily ascertained by taking apart the peripherals or from public sources on the internet therefore models but the accused products are generally mac computers right so roughly what order we talking about are you asking in terms of numbers of models yeah  right i'm just trying to figure it out because as i understand the bill of lading it only refers to the usage of a broadcom chip for one of the accused products where broadcom is supplying these chips and again in that letter there's no indication that apple's response to contention rod number one was insufficient but your honor in terms of trying to provide some cont for the questions you have asked about what is it that apple knew at various points in the case it's important to understand in that context that broadcom was the supplier of the accused chips and  supply source code with the proprietary mode in d s s was perfectly able in two thousand and fourteen and certainly from july two thousand eight hundred onward to pursue that discovery from broadcom in order to learn some of the things that this court has asked about with respect to apple's discovery responses and even aside from all of that your honor because they were accusing an optional feature of the standard that they could have and should have and eventually did based on publicly available information determine whether i will practice it there were many many reasons supporting the district court proper exercise of discretion in finding that d s s was not diligent and that it was far too late in the case to reinvent its infringement theories unless there are further questions thank you your honor thank you two thousand one hundred production apple produced over a one million pages of documents that should have been produced back in two thousand and fourteen that's an example of the discovery misconduct if you will that explains why  as long as it did but the elephant in the room is the answer to the question of why didn't you disclose in the in iraq and our answer in two thousand and fourteen the question was asked and the answer is apple has no legitimate justification for not disclosing it and only in june of two thousand and nineteen discovery misconduct in the invasive and incomplete misleading answer is plain to see concludes that proceeding for this morning thank you thank you very much the honorable court is adjourned from day to day