Continuity mistake: Kevin sawed the ladder front to back but later when Harry Lime climbs the ladder it is shown side to side.
Continuity mistake: When Harry slips off the ladder outside, he falls backward towards the pallet on the ground (a few feet away from the ladder), but then suddenly the green slime falls from the ladder straight down onto his face. The slime would have landed on his feet or maybe legs, but by this time his face was well clear of the ladder.
Factual error: The AA flight number to Miami is a 4 digit number beginning with a 5. These are regional flight numbers but the family flew on a mainline 767.
Continuity mistake: Kevin takes photos of the Wet Bandits robbing Duncan's Toy Chest. Later on when the police look at a photo, it doesn't match up to when it was taken - they didn't have money in their hands.
Continuity mistake: When Harry and Marv are climbing down the rope, Marv goes first. There is a low shot looking up at them and you can see Harry's head look over the roof. The next shot is looking right at Marv as he starts to climb down. Harry has vanished.
Answer: He's heading back to the hotel most likely to apologize for spending such a huge amount.