The plaintiff, Radware, planned to present damages theories in its closing argument seeking more than twice the damages that its retained expert on damages computed. The district court noted that "[w]hile expert testimony is not always required to prove damages, any damages theory must have evidentiary support. Radware had a duty to disclose its damages theories and evidence under Federal Rule of Civil Procedure 26(a)(1)(A)(iii) and in response to F5's discovery requests and this court's orders. Radware attempted to do that by pointing to the calculations of its expert Mr. Malackowski. The permissible scope of Radware's damages contentions at trial is thus limited by Radware's pretrial disclosures--including Mr. Malackowski's expert report--and, to the extent that the court allowed it, Mr. Malackowski's revised report served on February 27, 2016."

The district court determined that Radware should not be able to present argument in closing that were not disclosed in the damage expert report: "in closing arguments, Radware may not present any damages arguments or calculations based on LTM alone, DNS Lite,3 inactive modules, percentages of users calculated based on the data underlying the TechValidate survey, lost profits for GTM add-ons or virtual editions, 'off-box' combinations of GTM and LTM, or any other area outside the scope of Mr. Malackowski's calculations as limited by this court's orders, and as Mr. Malackowski presented at trial."

The district court explained its ruling that Radware was not "necessarily required to present expert testimony on these topics." But the district court explained that "[i]f Radware wished to present these damages theories, however, Radware was required to disclose these theories to F5 well before the close of discovery and certainly well before Radware rested its case at trial. Despite this court's order nearly three weeks ago suggesting that Radware could submit an offer of proof on what additional damages it wished to seek, Radware failed to bring its additional theories to the attention of F5 or the court until the evening before closing arguments and then said it preferred to disclose its new theories in camera so that F5 would not have a preview of Radware's new theories."

Accordingly, the district court granted F5's motion to preclude Radware from presenting undisclosed damages theories.

Radware, LTD v. F5 Networks, Inc., Case No. 5:13-cv-02024-RMW (N.D. Cal. March 10, 2016)