The One With the Sharks - S9-E4
Revealing mistake: While Monica and Rachel are talking about Chandler's "jollies to Jaws" Rachel's wearing a colorful flowery top, and after Joey walks in just as Monica takes her seat at the table in the closeup, it's Jennifer Aniston's stand-in, wearing a blue top, who is seated beside Monica. Rachel's hair is wavy in the flowered top, but straight in the blue top (viewed in widescreen). (00:12:22)
Visible crew/equipment: When the son of the accident victims is being led through the trauma rooms to see his parents' bodies, you can see Laura Innes crouching under a table in the background directing the scene. Innes was the director of this episode and it was established that this episode took place on her character's day off. Therefore, she should not have appeared in front of the camera at all. (00:32:30)
Neogenic Nightmare Chapter 5: Mutants Revenge - S2-E5
Continuity mistake: The size of the hole that Wolverine climbs through increases drastically. (00:07:45)
Continuity mistake: In the opening credits for Season 1, when Tony is stepping into the Iron Man armor, at first you can see the bottom of his pants go all the way down to his shoes. When the shot changes, his paints are raised and you can see his socks. (00:00:20)
The Origin of the Fantastic Four: Part 2 - S1-E2
Continuity mistake: When the reporter is getting an interview from the warden, her hair is suddenly less poofy than it was in the previous shot. (00:03:18)