Continuity mistake: When the guys of Station 51 are dealing with the rescue of the doctor from the radioactive lab, Johnny's, Chet's, and Marco's SCBA cylinders change during this scene while they're all wearing them. Differences such as tall, slim, with a flat top vs short, wide, with a rounded top, and also the writing on the tanks. Marco's even changes between shots, when he exits the lab's doorway.
Continuity mistake: While cutting the shaft where the burglar is trapped, in the close-up of Johnny taking the K-12 from Roy we can see the ladder that Roy's standing on, and when it cuts back to Roy after Cap's closeup, the ladder Roy's standing on has switched around to the opposite way.
Continuity mistake: While Brackett is treating the man who was in a fight, it cuts to Early walking down the hallway, and in the shot from the hallway he's entering treatment 4 which is beside the nurses' station, but in the next shot from inside the room we see he's actually in treatment 2, the one beside the receiving entrance.
Continuity mistake: Before 51's guys rescue the burglar trapped in the air conditioning duct, Vince's helmet has a highly polished and reflective surface, but when Vince reads the Miranda rights he's wearing a different helmet, it now has a matte surface.
Continuity mistake: When Roy tells the other guys of 51 what they need to do to rescue the doctor, once they're in the hot room, in the wide shot Roy's holding the handie-talkie in his right hand as he's gesturing with that hand, but when it cuts to Roy's closeup the HT has vanished from his right hand, as he's still gesturing.
Continuity mistake: When Johnny and Roy go into the radioactive lab, Johnny removes his glove to check the doctor's carotid pulse and when they walk through the doorway both his gloves are off (he's holding them), but in the next shot exiting the doorway both of Johnny's gloves are back on.
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.