This episode was the one that premiered the series, not the pilot. That's why there are only 21 episodes plus the pilot.

Gibbs poses as an inventor to investigate a murderess involved in industrial espionage.

This script was written to accommodate Anissa Jones (Buffy), whose leg was actually in a cast at the time. 

The maimed-leg prank was really way-out gross. But it seems that is the kind of weird humor the show handles.