Visible crew/equipment: When Gage and DeSoto are at Harry Teal's house for the third time, there is an actor's white tape mark on the floor in front of the cabinets, just below where the Biophone is placed.
Visible crew/equipment: When John and Roy are dispatched to the couple's house, for the second time, after they've checked the rooms upstairs and downstairs they join the couple in the living room, and the reflection of the large overhead set lighting is visible in the mirror hanging over the mantel.
Visible crew/equipment: During the rescue of the man trapped in the submerged car, when 110's Captain is handing John and Roy (who are in the water) the cave-in gear's air hose, in the shots from behind him on deck, the reflection of a crew member wearing white pants can be seen on the chrome surface beside him.
Visible crew/equipment: The first three times that Squad 51 is dispatched to 1012 Clinton Drive, before they leave the apparatus bay, we can see the reflections of set lighting in the squad's spotlights, particularly the driver's side.
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.