Who's the Boss: Part 2 - S4-E13
Continuity mistake: After Lisa puts out the fire, a sandwich keeps appearing and disappearing from the plate.
Who's the Boss: Part 2 - S4-E13
Other mistake: Robert Hegye's character in the show is called Sal but is credited as Al.
Who's the Boss: Part 2 - S4-E13
Revealing mistake: When Joe's brother punches him you can see that he misses.