Unbelievable: Part 1 - S13-E23
Other mistake: When Zoey watches the assault video of her, when Luke or Neil put their hand down on Zoey's leg, a few milliseconds before that there is another left hand, wearing a watch, but that can't be Neil's hand either because his other hand is right on Zoey, and so is his body.
Continuity mistake: When Miles and Winston are in the pool house, Miles is behind Winston while talking, but right when Miles says "all right, well either way" he is suddenly right in front of Winston.
Continuity mistake: When Miles and Winston are entering the house to confront Frankie, if you look on the ground you can see wet pool footprints, but nobody was in the pool. A bit later on when Frankie goes in the pool there are more wet pool footprints, which must be from previous takes.
Visible crew/equipment: At Miles' party when Zoey and a random girl yell and say "Who's ready to have some fun tonight!?", you can see the set and other stuff visible on the top left of the screen. (Mostly visible on widescreen version). (00:07:25)