Continuity mistake: When Johnny, Roy, and Captain Stanley are rescuing the people trapped inside Olive View Hospital, they are wearing distinctively marked SCBA tanks on their backs, and when all three firemen exit the doorway, Cap is wearing an entirely different tank, and the tanks that Johnny and Roy are wearing have been switched. Then when Johnny jumps off Engine 82, his tank differs again, and when he walks over to the Battalion Chief it's changed yet again.
Continuity mistake: When Batman and Robin guest star on the show, Batman's cowl changes from covering his neck to exposing his neck.
The Squawman - S2-E5
Continuity mistake: Right before the bad guy fires his rifle through the window, Caine kicks the rifle out of his hands and the bad guy jerks backwards, away from the building. The next shot the rifleman still has the rifle in both hands, and is slammed into the building by Caine.