Continuity mistake: When Jake Fratelli is in jail, the position of the sign on his chest changes between the first and second shot. The right tip is first touching his chin, and a frame later it's 15 cm below.
Continuity mistake: When the cop is reading Jake's suicide note the distance between one side of the scarf and the other keeps changing between shots.
Continuity mistake: When Data is about to slide through a cable to enter the house, the sky swaps from bright blue coloured in the close-ups to yellowish early dawn type in the wide angles.
Continuity mistake: During the initial chase, the way Data's sweatshirt folds over his utility belt keeps changing through shots.
Continuity mistake: When the boys run out on Brand and Mouth flattens his tires, Mikey is wearing a denim jacket. When they are looking for the restaurant after riding their bikes, he is wearing a yellow coat over his denim jacket he didn't have with him when he left the house. Mouth also suddenly has a raincoat over his jacket.
Continuity mistake: When Chunk kicks over the frame with Chestor Copperpot, it then shows his arm picking up the frame. The arm/hand shown in the close-up is an adult's, which is older-looking and hairier than Chunk's very young, chubby arm/hand.
Continuity mistake: The amount of jewels in the person's hand change position, size, and shape in the span of two shots near the end of the film when everyone is looking at them.
Continuity mistake: When Data starts being pulled towards the bin, the first shot shows him a half foot away from the bin. The second shot shows him several meters away from the bin. Then the third shot that shows Data falling into the bin shows him only an inch away from the bin at the start of the shot. (00:04:05)
Continuity mistake: The gang never take their coats with them after leaving the house, and there wasn't anything for them to put the coats in. Yet they somehow have their coats when they get to the restaurant. (00:23:30 - 00:27:10)
Continuity mistake: At the start, when Data's suction dart attaches itself to the orange drum, there are tall metal pieces of junk behind the grey drum which disappear, as the orange drum is being pulled forward toward Data. (00:03:55)
Answer: According to Mikey and Mr. Walsh, one of his crewmen must have taken the map and fled when One Eyed Willie was murdering his crew. This is substantiated in the novelization.