Continuity mistake: In the cornucopia bloodbath, the District 3 girl can be seen lying dead next to Cato when he picks up the water container, yet only moments later you see her in the distance of one shot being killed by a boy tribute (being slashed to the neck).
Continuity mistake: During the scene when Katniss is looking for Peeta, Katniss wades across the river. When she steps out she is wet up to her thighs. When the camera changes directions, and she sees the blood, her bottom half is dry, even though she was just in water.
Continuity mistake: Just after Katniss and Peeta use the healing cream, the wound on Katniss' forehead goes from healed/dry to fresh and then healed/dry again. (01:52:00)
Continuity mistake: As the tributes' chariots roll into the stadium, the Capitol citizens are throwing flowers to the tributes as they pass. When all the tributes are gathered at the end of the roadway, an overhead shot is shown and the runway is clean and flower-free. (00:33:15)
Continuity mistake: When Katniss, Peeta and Cato are on top of the Cornucopia, the blood stains on Cato's hand keep disappearing and reappearing when the camera switches between Cato and Katniss. (02:00:30)
Continuity mistake: In the scene where Katniss uses the remote to change the scene in her bedroom window in the Capitol, her hair starts out stringy (having just been taken out of the braids she wore in the opening ceremony) and changes to full and beautiful and switches positions around her face and shoulders as the scene progresses. (00:34:10)
Continuity mistake: When Caesar Flickerman is interviewing Katniss on TV, a chunk of her up-swept hairdo keeps changing, hanging down next to her left cheek in one shot, then it disappears in a close-up, then it's hanging down again. (00:56:15)
Continuity mistake: When Clove, the knife-wielding girl from District 2, attacks Katniss, the sun's position changes in every shot. (01:52:00)
Continuity mistake: When Katniss is saying goodbye to Gale, just before she is taken away for the games, there is a small curl of hair hanging down the left side of her neck that can be seen in all the shots when the camera is behind her. Whenever the camera angle changes to a face shot, the curl of hair disappears.
Continuity mistake: In the scene where Katniss is being interviewed by Caesar on stage before the games, her hair is securely up kept in the back. As she is twirling to show off the flames, you notice her hair has come undone a bit and is drooping in the back. By the end of her twirling, her hair has returned to its previous secure up-do. By the end of the interview, her hair is sagging once again in the back. Then, returning backstage with Haymitch and Effie, her hair has returned to being secure and neat. (00:56:20)
Continuity mistake: The tracker jacker nest Katniss is trying to release by sawing off the branch it hangs from, is alternately shown resting on another branch, then hanging freely. (01:23:25)
Continuity mistake: At the reaping, As Effie says "our tributes from District 12" the camera pans from Peeta to Katniss. Katniss has her hair to the side of her left eye. Camera changes and now her hair is in front of her eye. (00:16:50)
Continuity mistake: When the tributes are entering the arena on horse-drawn chariots, the spacing between the vehicles keeps changing from being far apart (in the long shot) to bunched up in closer angles. This is not just because the horses either sped up or slowed down because the distance is always perfectly even between each chariot. (00:30:50)
Continuity mistake: In the scene where Effie Trinket pulls a name out of the glass bowl, she opens it and the black tab is on her right. She clears her throat, the camera angle changes, and the black tab is suddenly on her left. (00:14:25)
Continuity mistake: When Katniss is retrieving the second parachute (the one with the soup), the piece of paper with Haymitch's message changes between shots (the corners are / aren't torn) and they way Katniss is holding it also changes (from below / from the side). (01:45:10)
Continuity mistake: When Katniss finds Peeta with the nightlock in his hands she gets angry with him for scaring her and hugs him. In the close up shot, Peeta has both his hands around her back with his right hand above his left. He says, "I'm sorry" (twice) and the next shot shows his left hand above the right. (01:54:50)
Continuity mistake: In the scene where Peeta is throwing the huge metal ball, you all know that Cato, Marvel and Glimmer are watching. In the 2 last shots where the 3 of the are shown, Cato's stance is shifted. The first shot is zoomed out where you can also see the metal ball, in this shot Cato is standing with his arms hanging and slightly rotated to his right side. You can see him move to the left side, but in the shot directly after he is standing rotated to his left with his arms crossed. (00:40:05)
Continuity mistake: The small wound on Peeta's left eyebrow changes size through the film.
Continuity mistake: When Katniss and Prim are entering the square, Prim panics and Katniss tries to calm her. During that dialog, Katniss' hands suddenly appear holding Prim's face. (00:11:00)
Continuity mistake: When Prim and Katniss are talking just after the reaping, Katniss grabs Prim's chin. Camera cuts to behind and her hand has gone. (00:18:50)
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 ★