Defendant's Motion for Leave to Amend Invalidity Contentions Denied Where Defendant Disclosed Prior Art to Plaintiff But Waited Four Months to File Motion for Leave to Amend

Defendant Green Max Distributors, Inc. ("Green Max") filed a motion for leave to amend its invalidity contentions. In the motion, Green Max sought to add photos, publications, and prior-art references to its original invalidity contentions. These additional references included additional photos that "more clearly and from different angles" depicted the prior art, full versions of the publications that depicted the prior-art references, nine newly cited publications, and eleven newly cited prior art references.

Green Max moved to amend its invalidity contentions in August 2013. Nonetheless, Green Max asserted that it was diligent because it provided Hydrodynamic with many of the additional references it sought to include, asserting that it provided Hydrodynamic with updated invalidity contentions containing "most" of the additional references in response to an interrogatory on February 20, 2013, and then disclosed some of the additional references at Green Max's deposition of Hydrodynamic conducted on July 16, 2013. The district court found that this argument was irrelevant. "But Green Max's disclosure of the prior art to Hydrodynamic is irrelevant to the diligence inquiry. Green Max must have been diligent in discovering the new prior art and in bringing its motion to amend its invalidity contentions--not in its disclosure to Hydrodynamic."

Indeed, Hydrodynamic used the April disclosure to assert that Green Max had been aware of the need to amend its invalidity contentions since at least April 2013. Hydrodynamic's therefore argued that Green Max waited until July 31, 2013, nearly four months later to file the motion.

The district court found this argument persuasive. "Nowhere in its Motion does Green Max attempt to explain this almost four-month delay. Both parties agree that Green Max (1) provided Hydrodynamic with updated invalidity contentions in February 2013, (2) received Hydrodynamic's April email urging it to amend its invalidity contentions, and (3) utilized the prior art in its July deposition. And yet at no time in this period did Green Max move to amend its invalidity contentions. Quite simply, Green Max's failure to timely file its Motion is baffling."

The district court also found that Hydrodynamic would be substantially prejudiced by the amendment because the discovery cut-off date had passed. "Although Hydrodynamic has not filed any substantive motions that would be impacted by Green Max's amendment, the August 5, 2013 discovery cut off date has long passed. Permitting amendment at this time would prejudice Hydrodynamic who is no longer able to conduct discovery regarding the various new prior-art references."

Accordingly, the district court found that Green Max has failed to establish diligence in seeking amendment and that there would be prejudice to Hydrodynamic due to the lateness of the amendment and, therefore, it denied the motion for leave to amend the invalidity contentions.

Hydrodynamic Industrial Co Ltd. v. Green Max Distributors, Inc., Case No. 2:12-cv-5058-ODW (JEMx) (C.D. Cal. Aug. 29, 2013)