Continuity mistake: When the boy enters the Christmas tree tent he encounters a "guard cat", which is alternately sitting and lying down each time the camera changes.
Continuity mistake: During the scene where the unaccompanied minors are in the unclaimed baggage room, Charlie finds a tape player in an unclaimed suitcase. He turns it on and starts dancing while holding it. The shot switches to one of the children, and in the next shot, the tape player is still playing, but it is not in Charlie's hand anymore.
Continuity mistake: After looking through the unclaimed luggage for something to pursue the children towards the hotel, the guards catch up too fast. In particular, the guard who jumped a hill in a tire, and ends up rolling, should never have passed them.