Plot hole: After Storm's attempt to escape the Genoshan prison is thwarted, she ends up in the ocean right at the shoreline of the beach, where she is captured by a Sentinel. Aside from the fact that it makes no sense for a Sentinel to be hiding in the ocean in the event that a mutant tries to escape the prison, there is absolutely no way that a two-story tall robot could hide in the ocean right by the beach, as the water would be way too shallow. You can even see that the water level only goes up to the Sentinel's ankle area when it is standing upright in the ocean. (00:03:15)Phaneron
Plot hole: In this episode, a very star-struck Paul meets Jerry Seinfeld on the street. It's not clear whether Jerry is playing himself or his Seinfeld character, but either way it's a mistake. If Jerry was playing himself, it's a mistake because Mad About You did a crossover episode with Seinfeld in its first season, so it would be impossible for Seinfeld (the TV show) or Jerry Seinfeld the actor to exist in the Mad About You universe. If Jerry was playing his character, it's a mistake because it was established in that crossover that Paul and Jerry used to be neighbors and knew each other fairly well, so Paul wouldn't be at all star-struck.