Revealing mistake: En route to the pick-up truck hanging from the freeway on-ramp, there is a flipped shot of Engine 51 and Squad 51 as they drive under the freeway before the camera pans in towards the car. Some giveaways are the reversed '51' on Engine 51 and the reversed 'road construction ahead' sign.
Revealing mistake: When Johnny climbs up to the roof to get Sheba down, Johnny has two long shadows, one from the sun and one from the set lighting.
Revealing mistake: When Johnny and Roy are in the storm drain searching for the two missing boys, all the walls have very distinctive water stains and markings, and the same walls and drains keep repeating, no matter the distance they have walked.
Answer: I believe you are speaking of the old man, Mr. Wilson. He's played by J. Pat O'Malley.
Bishop73
Correct, it was J. Pat O'Malley...he also played the grandfather with his grandson when their rocket exploded, and also played "Old Bill" in the episode with Ann Prentiss, where Gage saves the little girl from the burning tree house, and her mother falls in love with him.