Other mistake: Throughout the episode, characters make reference to Mark's Grandma having a wooden leg, including the woman herself. However, both of her legs are visible from the knee down several times in the episode, and you can see both of them are flesh and bone.
Hangin' with Mr. Cooper (1992)
1 other mistake - chronological order
Starring: Raven-Symone, Holly Robinson Peete, Mark Curry, Marquise Wilson
One on One - S5-E7
Revealing mistake: When Coach Norris matches Mark's dunk in their game of HORSE, you can tell that she uses a trampoline or some other kind of apparatus that's off screen to assist her in her jump.