Watch Out: Lack of Diligence When Amending Contentions Can Lead to Preclusion

A party needs to be cognizant of the infringing instrumentalities it identifies in its infringement contentions and any subsequent amendments. In LMT Mercer Group, Inc. v. Maine Ornamental, LLC et al, No. 10-4615, 2014 U.S. Dist. LEXIS 5719 (D.N.J. Jan. 24, 2014), Judge Wolfson denied Plaintiff LMT Mercer Group’s (“LMT”) motion to amend its infringement contentions to add a product that it removed from its previous filings and then delayed in correcting that exclusion.

LMT filed a complaint for patent infringement against Defendant Home Tops, LLC (“Home Tops”) in December 2010. LMT identified Home Tops’ Polaris Light product in its Complaint and its infringement contentions under New Jersey’s Local Patent Rule 3.1. LMT’s original infringement contentions were served on December 14, 2012. Subsequently and at the request of Home Tops, LMS served Home Tops with supplemental infringement contentions on January 29, 2013. The supplemental contentions contained almost all of the same alleged infringing products, but did not identify the Polaris Light product.

During the mediation period, LMT sought to amend its infringement contentions again. This time, Home Tops informed LMT that it would not consent to any amendment that included the Polaris Light product. On March 8, 2013, LMT moved for leave to supplement its infringement contentions without including the Polar Light product. The motion was unopposed and was granted.

During the same time as the March 8th motion, LMT became aware of another product that was infringing on the patent-in-suit, the Magena Star product. LMT notified Home Tops of this alleged infringement. While the March 8th motion was pending, Home Tops moved for partial summary judgment on the issue of waiver. LMT immediately moved for leave to amend its infringement contentions to include the Polaris Light, Magena Star, and similar products.

New Jersey Local Patent Rule 3.7 allows amendments to contentions “only by order of the Court upon a timely application and showing of good cause.” (emphasis omitted). In determining whether an amendment should be granted, Judge Wolfson applied a two-step approach:

  1. Determine whether the party seeking to amend acted diligently in filing its motion.
  2. Only if diligence is found, determine whether the non-moving party would suffer prejudice as a result of the amendment.

With respect to the issue of “good cause,” LMT argued that the Polaris Light and Magena Star products are one in the same. The Court rejected that argument and held that “arguments do not provide the requisite good cause required by our local patent rules to explain why LMT removed the Polaris Light from its infringement contentions in the first place in January 2013, and decided not to seek amendment until July 2013.” 2014 U.S. Dist. LEXIS 5719, at *21. The Court denied LMT’s motion to add the Polaris Light product to its infringement contentions. Id. at *22.

On the other hand, the Court did find that LMT acted diligently in seeking leave in respect to the Magena Star product. Id. at *24. It also held that LMT had good cause for doing so on the basis of newly discovered, non-public information and, the Court found that Home Tops would not suffer undue prejudice. Id. at *25.

Parties need to be as thorough as possible in identifying accused instrumentalities in their infringement contentions and diligent in amending those contentions when additional products are identified through discovery, particularly in jurisdictions with local patent rules such as the District of New Jersey.

Gibbons will continue to track the applications of local patent rules and their enforcement in limiting issues to be adjudicated.

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