Revealing mistake: (Part 4) After Omega takes off his mask and looks in the mirror, when he sees that his physical body doesn't exist he puts his mask back on and screams, but when he shouts, "If I exist only by my will, then my will is to destroy," Omega's mask pops up off his face, and we can see the actor's blackened face as he shouts the last bit of his dialogue. (00:07:10)
Super Grover
Continuity mistake: The date of Helen Kimble's murder is given here as Sept. 19, 1961. Previous episodes, however, had established it as occurring on Sept. 17, 1960.
Jean G
Deliberate mistake: During the 6/11/04 episode, Jax and Courtney are having dinner in Italy. Carly, who is in New York, does some sleuthing, finds out where Jax and Courtney are, and flies to Italy. Miraculously, Carly manges to fly from New York to Italy and arrive while Jax and Courtney are still eating dinner.
Allyson
Continuity mistake: In the scene after the second crash, when the pilot and his wife "borrow" the jeep to return to the base, the shot is flipped, reversing the positions of the husband and wife in a mirror image of the real vehicle, placing the "driver" in the passenger position and the spare tire, which should be on the near side, is now on the far side. In the next shot, as the vehicle nears the base, everything suddenly resumes the correct perspective.
Darryl
Who Killed Avery Lord? - S1-E23
Visible crew/equipment: After the woman in the negligeé goes back into her apartment, a crew member's shadow appears on the corridor wall. (00:42:00)
Jean G
That Little Old Matchmaker, Martin - S1-E12
Character mistake: In Bill's office, after Tim talks about the acoustics in the building, Bill calls Tim "Bill." (00:15:51)