Character mistake: When Katniss is trying to destroy the supply pile, we see a close up of her drawing back on the her bow. We see she has the arrow to the left of the grip, meaning the fletchings (feathers at the end by the string) have to be facing to the left. Otherwise the fletchings will hit the grip, rip off, and make the arrow unstable in flight and go completely off course. However, the fletchings are are facing to the right and so will hit the grip. Any archer or anyone who is skilled with a bow would know this. (01:32:45)
Character mistake: In the first movie, Haymitch is their mentor. When they are eating dinner in the capital, Peeta says his mother said district 12 may finally have a winner, and she was talking about Katniss. What does he mean by "finally have a winner?" Haymitch had already won the games for district 12 in the past. So Katniss or Peeta winning wouldn't be the first for district 12.
Answer: I watched this scene multiple times on YouTube. There is definitely something moving that probably is not supposed to be seen. I'd agree with your assessment that it looks like a hand. Most likely a film crew member is crouched on the floor performing some technical function during the filming. Just what it is impossible to tell. You should submit it as a "movie mistake."
raywest ★