Continuity mistake: Dr. Luther Brooks is in the changing room with Dr. Dan Wharton. During their conversation, one of the lockers behind Brooks' is open, its door quite close to him. In the close-ups though, all the lockers are closed. The shadows are also different. (00:04:00 - 00:04:40)
Continuity mistake: When Porky Pig arrives at the countryside, he places his easel next to a tree, but when we see a full view of Porky painting a little later on, the tree has gone.
Continuity mistake: Jim Hawkins is stabbed in the shoulder, but when the doctor later treats and binds the wound, it has moved to his upper arm. (01:20:25)