Although the Pennypack factors for exclusion are notoriously difficult to meet, judges in D. Del. have been excluding late-disclosed theories more frequently than in the past.
Case in point: on Friday, Judge Andrews granted a motion to strike DOE theories asserted for the first time in an opening expert report. The plaintiff offered a number of excuses for disclosing the theories when it did—"it was only able to collect evidence to support its new DOE theories" after a COVID-delayed source code review, it lacked supporting evidence until a technical deposition in November 2020, and so on.
Judge Andrews not only rejected these excuses, but took it a step further—coming very close to finding that the plaintiff acted in …