Revealing mistake: When Frasier comes into the chalet after skiing he doesn't show any of the visible effects after a hard day on the slopes. Meaning, his face isn't even flushed from the cold, his hair is perfectly combed after wearing a hat and there is not even a drop of snow on his boots.
Plot hole: Laura successfully knocks out both bad guys, steals their van and crashes through the warehouse doors. The van doesn't stall, but inexplicably, she stops it, gets out and runs away on foot, even though the baddies are coming to and coming after her. Not the option you'd expect a kidnap victim to choose: most people would floor it and keep on driving. (00:23:40)
Character mistake: When Alex mentions to Mallory that he's had sex before, he tells her he was 17 and that it was leap year. Not correct, this event occurred in 1982 (during one of the first episodes when Alex was 17), which was not a leap year.
Audio problem: When Rene comes upstairs to speak to Michelle the piano player in the background is out of sync with the music being played. (00:03:00)
Visible crew/equipment: When Larry says "of course we got a kid" the boom mic is visible.
Me and Mr. T - S1-E4
Continuity mistake: When the teacher is asking the class questions about the declaration of independence, she has some info about it written on the blackboard ending with "1776 in." Then facing away from the blackboard, she asks a question and Mr. T quickly answers and then only a second later, the camera is back on the teacher and suddenly the world "PHILADELPHIA" is on the blackboard under the "1776 in" with no time for her to have written that word in one second.
Testimony of Evil (Dead Men Don't Laugh) - S1-E6
Continuity mistake: At the start, the glass on the left is poisoned. The guy picks up the glass on the right, but still ends up dying.