Unicorn Energy AG v. Tesla, Inc., 5:21-cv-07476

Plaintiff Unicorn Energy AG sought relief from a Magistrate Judge’s order that partially denied Unicorn’s motion to amend its patent infringement contentions against Tesla Inc.
The amendments at issue were requested on the last day of fact discovery and pertained to Tesla’s Megapack 2 product, Powerwall+ bundle, and newly articulated theories regarding Tesla’s accused products.
Magistrate Judge Susan van Keulen denied the amendments on grounds including lack of diligence by Unicorn in seeking the relevant discovery or raising the contentions earlier in the litigation, and prejudice to Tesla given the timing.
Unicorn argued new theory amendments were based on documents and testimony only recently produced by Tesla, contending that Tesla's production delays justified late amendments.
Tesla responded that the information underlying Unicorn’s amended contentions had been available much earlier or could have been compelled sooner and that the late amendments would unfairly prejudice Tesla by disrupting the litigation schedule.
District Judge Beth Labson Freeman reviewed the Magistrate Judge’s order for clear error and ultimately denied Unicorn’s motion for relief.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether amendments regarding Megapack 2 should be allowed	Tesla's late production justified amendment; Unicorn could not have moved earlier	Information was available earlier or could have been compelled; Unicorn lacked diligence	Denied; no clear error—Unicorn not diligent, amendments untimely
Whether Powerwall+ bundle amendment should be allowed	Powerwall+ was covered by broad initial contentions; Tesla not prejudiced	Amendment untimely and nonspecific; adding new product at this stage would be prejudicial	Denied; local rules require specificity, lack of diligence justifies denial
Amendment regarding new "autonomous control" theory	Amendment tethered to initial contentions; no new theory	Amendments untethered and prejudicial; based on evidence that could have been discovered sooner	Denied; no clear error, amendment prejudicial and untimely
Amendment regarding "communication interface" theory	Amendment (based on recent discovery) wasn’t a new theory	Judge allowed amendments tied to timely discovery but struck new, late-raised theories	Denied; no clear error—stricken portion was a new theory from late evidence

Grimes v. City & Cnty. of San Francisco, 951 F.2d 236 (9th Cir. 1991) (sets clear error standard for reviewing magistrate judge pretrial order)
Apple Inc. v. Samsung Electronics Co. Ltd., 2013 WL 3246094 (N.D. Cal. 2013) (diligence is required for amending infringement contentions)
Illumina Inc. v. BGI Genomics Co., 2021 WL 2400941 (N.D. Cal. 2021) (lack of diligence ends inquiry for amendment motions)
Google, Inc. v. Netlist, Inc., 2010 WL 1838693 (N.D. Cal. 2010) (critical issue is whether information could have been discovered earlier with diligence)