In the scene where a kindergartener slaps Blade Steel on the back of the head Dwight Clark had an involuntary reaction where he roundhoused the kid and knocked his jaw loose. He later apologized and the actor's guardians decided not to press charges after Clark promised the actor a role in Kindergarten Ninja 2.
Dwight Clark was a NFL wide receiver for the San Francisco 49ers, making what has been know as the catch.
In the fight sequence in the restaurant Clark's On The Bay, lead actor Dwight Clark's no. 87 shirt is visible behind him on the wall.