Continuity mistake: When DeSoto and Gage arrive at Rampart their black helmets are not hanging in Squad 51, when they enter the hospital. A moment later, when they're dispatched, both helmets are hanging in their proper place behind the seat. The distance between the squad and ambulance has also increased.
Continuity mistake: Just as Gage and DeSoto walk into Rampart's staff lounge, while discussing practical jokes, DeSoto is holding the handy-talkie in his right hand, but in the next shot the handy-talkie has vanished.
Continuity mistake: After Squad 51 is dispatched to "possible heart case" when Roy and Johnny walk into the house, we can see in the hallway and there's a bureau against the wall, but when they leave that bureau is gone and now there's a painting on the wall which we should have seen in the earlier shot, but it wasn't there.
Continuity mistake: At the start, when Roy finds Johnny in the squad reading '1000 Practical Jokes', Johnny's window is rolled down, and Roy places his arms over the passenger side door then leans in to talk to Johnny, but in all of Johnny's closeups Roy's arms are gone.
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.