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.
Visible crew/equipment: During the rescue at the construction accident, when the man with the back injury is hanging from his line and is lowered after Roy untangles the block, we can see that in addition to the rope wrapped around the man there's wire and support that go under the man's jumpsuit. The wire/support are gone once he's lying on the balcony and they remove the rope.
Visible crew/equipment: Station 51 responds to a building collapse with the trapped boy, and when they enter the building with Tommy's friend, the actor's white T-mark is visible on the floor.
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.
Visible crew/equipment: At Rampart, when Gage and DeSoto walk into the staff lounge, where Dixie and Dr. Brackett are seated at the table, there is an actor's T-mark on the floor behind Dixie, where DeSoto stands.
Other mistake: After Roy has found the location of the boy trapped in the collapsed building, Captain Hammer gets on the handy-talkie and says "Engine 51, Stoker," but oddly enough the subtitles read, "Agent 51, Stoker." Subtitles from Universal Studios 2010 DVD.
Visible crew/equipment: On site at the construction accident with the back injury victim, when Roy climbs over the tower's railing we can see the yellow canvas strap attached through the leather loop of his lifebelt, but when he descends to the injured victim, the yellow canvas strap is now also attached to a carabiner protruding from under his turnout coat, by his pants, which presumably is attached to additional hidden support.
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.
Visible crew/equipment: On site at the construction accident, when the man with the back injury is lying in the stokes and being lowered with the ladder, a crew member/cameraman is visible on the landing at the lower right side of the screen.
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.