Ravin Crossbows, LLC v. Hunter's Manufacturing Company, Inc., 5:23-cv-00598

Ravin Crossbows sued Hunter’s Manufacturing Company (d/b/a TenPoint Crossbow Technologies) for infringement of six patents, later reducing claims to 37 after procedural developments.
TenPoint initially filed limited invalidity contentions, stating intent to supplement as its investigation progressed, and later served extensive supplemental invalidity contentions over 15 months later.
The disputed supplemental contentions included 33 new invalidity theories (many based on Stanziale I prior art) and new inequitable conduct allegations.
The local patent rules permitted some amendments without leave, but required timeliness and disfavored new theories meant to disrupt proceedings.
Ravin moved to strike TenPoint’s supplemental invalidity contentions as untimely and prejudicial; the court held a status conference and ordered formal briefing.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Timeliness of supplemental invalidity contentions	Supplemental contentions served too late, unfair surprise/disruption	Asserted amendments were permissible under local patent rules; complexity justified delay	Supplementing after 15 months was untimely and unfair, especially for undisclosed prior art
Undisclosed prior art claims	Surprise and prejudice due to lack of notice	Ravin knew of prior art, so no real surprise	Motion to strike granted as to claims based on undisclosed prior art
Stanziale I prior art claims	New theories require additional claim construction	Ravin knew Stanziale I was always part of TenPoint’s position	Motion to strike denied; Stanziale I claims allowed—no real surprise or prejudice
Inequitable conduct claims	Claims not pled or sufficiently particularized	Allegations based on attorney's supposed intent	Motion to strike granted; allegations too speculative and not pleaded with particularity

Wilson v. City of Zanesville, 954 F.2d 349 (6th Cir. 1992) (local rules cannot override the Federal Rules of Civil Procedure)
Howe v. City of Akron, 801 F.3d 718 (6th Cir. 2015) (lays out five-factor test for whether a failure to disclose is harmless or substantially justified)
Exergen Corp. v. Wal-Mart Stores, Inc., 575 F.3d 1312 (Fed. Cir. 2009) (summarizes the heightened pleading standard for inequitable conduct under Rule 9(b))