Character mistake: When Mr. Grady, the self defense instructor, and his wife are in the ER waiting room after Brackett taped up his fractured ribs, Mr. Grady makes a comment about being flipped, and instead of saying Mrs. Pestone he says the name incorrectly as Prestin, then a few moments later he says her name properly, just as he did earlier during the class.
Fair Fight - S6-E5
Character mistake: When Squad 51 is dispatched to the fighting couple the first time timeout is 10:12, and the second call to that house timeout is 12:37. When Roy and John are there the first time, it's for no more than five minutes. Then when they're there the second time, Roy says "Please folks, we just went through this less than an hour ago," though it was over two hours when they left the fighting couple the first time.
Captain Hook - S6-E8
Character mistake: When Johnny and Roy are with the heatstroke victim in the polar bear costume, they're on different sides of the victim when Roy says, "Twitching here in both arms," and Johnny looks at her left arm and responds, "Yeah, the same thing over here too." And then it happens again, when Roy says, "Got some heavy spasms in these arms," and Johnny responds, "Yeah, same thing over here."
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.