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 4: The Mutant Agenda - S2-E4
Continuity mistake: When Professor X is explaining his line of work to Spider-Man, the neck portion of Gambit's headgear is flesh-colored. (00:04:35)
Continuity mistake: When Tony is setting the timer, the appearance of the control panel completely changes when Julia is asking him if the person who reprogrammed his other satellites takes control of the one he is setting up. (00:10:37)
The Origin of the Fantastic Four: Part 2 - S1-E2
Continuity mistake: During the jailbreak scene, the heavyset inmate is shown wearing ripped pants that go just below the knee, which becomes a speedo when Slash punches out the guard. (00:03:06)