When Buffy and Riley wake up, the bed is lying crooked, but when they stand up the bed is straight again.
After Oz says "Pretty much now" in the van, and the shot shifts to Willow, after a few seconds we can see Oz leaning in for a hug. When the shot switches to Oz the next second, he's leaning back again, just to lean in for a hug again after a few seconds. This is only visible in the expanded-to-widescreen version, not in the originally intended 4:3 frame.
At 9:30, when one of the soldiers is thrown against the trunk of a tree, it wobbles in a way that makes it obvious it is a prop and not a real tree.
Having rescued Riley and after getting Oz out of his cell in the initiative, Buffy and the gang get into the elevator. As the elevator door closes, you can see the handle on the right hand side used for pulling the door open, and the fingers of the crew member pushing the door closed. This is only visible in the expanded-to-widescreen version, not in the originally intended 4:3 frame.
When Willow and Oz hug in the van towards the end, Willow leans forward and the wireless transmitter becomes visible on her lower back.
The boom operator is clearly visible in the mirror in Willow and Buffy's room in two separate shots.
Riley acts as though he didn't know about Willow and Oz's break up but he was around when she was going through her depressive stage.
Willow leaves her room to go to the bathroom and almost immediately Tara knocks on the door. The interval between Willow leaving the door and Tara knocking is so short, it's impossible that the two didn't see each other in the corridor.