(at around 48 mins) When Cliff goes to Tim's room, he is wearing arm bands with his shirtsleeves pulled down over them. When he enters the room, they are gone, but at the end of the boys' fight, they have returned.
It is illegal to profit from the proceeds of a crime, even if one is not the criminal. Therefore, Tim would not have been able to use the stolen money to become the owner of the garage. This is an odd oversight on the part of the Hays Code.
(at around 36 mins) When talking with Jimmy, a fly can be seen on the back of Cliff's jacket. However, this is not a goof as flies do get into buildings and often land on objects or people.
The train leaving Sing Sing is moving backwards (note the locomotive is missing from the front, but a steam whistle is heard), and it is shown going north, not south towards New York City.
However, the train is a Long Island RR commuter train, which is powered by an outside third rail; there is no locomotive. The whistle heard is an air whistle sounded by the train's air brake pressure.
However, the train is a Long Island RR commuter train, which is powered by an outside third rail; there is no locomotive. The whistle heard is an air whistle sounded by the train's air brake pressure.
Cliff arrives home from prison and unwraps a parcel and puts the contents on the dining room table. Later, when Peggy and Tim arrive, Mrs. Taylor is seen holding a beaded purse, which appears to be what Cliff brought home. Nothing is mentioned about the item, so there must have been a deleted scene.
When Tim is wheeling his motorcycle into the back of the garage after taking Chuck to meet his girlfriend, shadows of the police waiting inside are visible on the garage door, ruining the surprise that they are laying in wait for him.