Revealing mistake: In Jonathan, Warren and Andrew's van, whenever they're watching something on the monitors fed from their security cameras, you can see that the footage is actually pre-recorded due to the fact that the footage is being played through QuickTime media player.
Revealing mistake: The entire scene where Buffy is experiencing accelerated time, shadows of trees move in the wind but never actually grow or shrink. Even over short increments of time, the sun can move shadows noticeably, and judging from the speed of the people around her, Buffy is in accelerated time for at least half an hour.
Plot hole: In the 3rd time loop at the magic shop, the woman looking for the mummy hand looks surprised when Buffy knows what she wants. In the 2nd time loop, the woman tells Buffy that she called the shop 20 minutes earlier and was told that they had one. Therefore at least one of the shop's staff would be aware that a woman would be arriving looking for a mummy hand.