In the jump-rope scene, Sailor falls down in one shot while Punchinello recites "Mabel, Mabel". But after the rope changes into two double dutch ropes, he stands up in another shot with Peter. In yet another shot, he sits down on the floor while next to David and Peter who are standing on the left side.
In the background of one of the scenes, while Minkey Monkey is sitting on his shelf, he blinks his eyes twice (long before the Hokey Pokey group even comes to life).
During the Lassie/Laddie scene, the bagpipe keeps playing even though Lassie has stopped "playing it."