Continuity mistake: When Haymitch is talking to the head peacekeeper, the cut on the peacekeeper's forehead disappears in some shots and reappears in others. (00:36:10)
Continuity mistake: When Peeta hands Katniss the pearl, the amount of sand on his hand increases drastically instantly. (01:42:50)
Continuity mistake: When Katniss is stood in the square, and Haymitch is talking to the peacekeeper, her hair is either in her face or not depending on the shot. (00:37:50)
Continuity mistake: Just as President Snow starts to give his speech we see Prim, Katniss and Mrs. Everdeane sat on the sofa. Mrs. Everdeane has her legs crossed in one shot and side by side in the next. (00:43:45)
Continuity mistake: When Gale and Katniss are talking atop the hill about how they should have left earlier, Katniss removes her hand from Gale's neck/face. The camera cuts to the other side and her hand is back there. (00:47:30)
Continuity mistake: Effie motions Katniss down the steps of her house and her arms are outspread. Camera cuts to a view in front of Katniss and Effie now has her hands on Katniss' back. (00:12:20)
Answer: He was probably very upset from thinking about Rue and couldn't manage engaging Katniss more without breaking down.