Continuity mistake: In the flashback to when Oliver brings a pizza in and puts it on the bed, the box goes from open in one shot to closed in the next. (00:28:30)
Continuity mistake: During the hallway gauntlet, Oliver takes a guy out and ends up on his left knee. He then starts to turn right and draws an arrow, which doesn't make any sense because he holds his bow with his left hand and can't get a good shot from that position. What's more, in the following shot, he is turning to his left.