Revealing mistake: When the bus is being pursued, Smith steers it to trip several prepositioned explosives that blow up trees to block the road. In order to by pass a downed tree the Germans push a motorcycle around it, and you can plainly see that the tree was cut by a chainsaw. (02:18:40)
Other mistake: Just before the Charger crashes, a tow bar connecting both vehicles is visible on the Mustang's front bumper.
Continuity mistake: When Dave begins to disconnect HAL's circuits, one angle shows him unlock the first, second, then third unit. Just as he's about to remove the key from the third lock, the angle changes and he's pulling the key from the second lock and then goes for the third again. We know this is consecutive time as HAL is pleading with Dave the entire time. (01:51:45)
Continuity mistake: When Mr Bumble and the female workhouse employee take Oliver to the Governor's office, Bumble raises his hand and knocks on the door. The woman sings "They will lay the blame on the one who named him", prompting Bumble to move his hand away from the door, toward his face, as if he's about to place it over his mouth in concern. The camera then changes angles and Bumble's hand is suddenly lowered and nowhere near his face.
Visible crew/equipment: You can see the cameraman, camera, and a crew member reflected in the school bus window as it drives off. (01:17:20)