Continuity mistake: When Larry Bird hands Marty the pie, Marty takes it with one hand and then grabs it with his other hand. In the next shot, the pie is no longer in his hands and he's seen grabbing it with both hands at once.
Mo Purses Mo Money Mo Problems - S1-E21
Continuity mistake: When Marty grabs the puzzles from Jackie Joyner-Kersee, he has the newspaper tucked under his arm. It's still under his arm when he says maybe doing puzzles with Max is their thing, but in the next shot, the paper is in his hand. It's back under his arm in the next shot.
