[zoomzoom]

The first "It's Over" definitely was meant for her to sing, because she takes the mic up to her mouth half way through the phrase and makes her singing movements with her head and arms. The whole file did have a slight delay, but not that much.

On the other hand, she doesn't seem startled or anything, just moves the mic slowly up to her mouth, so it could be a delay from that particular camera.

*Edit: Though when she continues to sing from that angle, it matches perfectly. Hmm. The song definitely did not sound lip synced, it was a bit pitchy. Then the "it's over" parts could be prerecorded, but why on earth would they do that.