Other mistake: While the guys are in the kitchen, deciding whether or not to keep the dog and then what to name him, when Chet is drinking the milk, we can see the red tape covering one side of the container to hide the brand name and logo.
Other mistake: When Squad 51 is dispatched to the movie studio, while en route in the interior shot, in the rear-view mirror we see the reflection of the driver's helmet, and it has an 18 on it, instead of 51.
Other mistake: During the structure fire at the Atlas Hotel, when Roy and John are with the unconscious man being given proper CPR by civilians, it is too painfully apparent that the man giving rescue breaths is just leaning over the man's face, nowhere near the victim's mouth, particularly after Marco and Chet drop off the stokes.
Other mistake: When Brackett's on the line with Johnny, who's with the quarterback on the field, Brackett has the third button (out of five) pressed to record the conversation on the tape machine. However, in episode 2x5, "Peace Pipe", Brackett presses two buttons - the third and fifth, when Squad 51 is at the scene of the drunk driver's accident, and in 2x10, "Dinner Date", Dixie presses the second button to record, when Squad 51 is with the little girl whose arm is stuck in the pool drain.
Other mistake: After Roy tells Captain Stanley, over the HT, that he and Johnny may have found something in the flooding storm drain, Captain Stanley uses his HT to contact Marco and Chet (who are driving Squad 51 while John and Roy are down below), and says "Squad 51, Engine 51..," but the subtitles read, "Car 51, Engine 51..." Subtitles from Universal Studios 2010 DVD.
Other mistake: When the tones drop and Station 51 is dispatched to the "structure fire", there's a closeup of all the guys running from the kitchen and the back heading to the squad and engine, and none of them are actually 51's guys.
Other mistake: When Squad 51 is dispatched to the 'child in a coma', the address is given as "3705 Orchard", but when they park on the building's corner the street sign reads Colfax. As an aside, this is the same location/footage that is used in 2x5, "Peace Pipe", with the address given as "1017 Crocker" in that episode.
Other mistake: When Station 51 is dispatched to the structure fire in the middle of the night, once they arrive at the burning house, one of the first shots shows a crowd of bystanders, many in their robes. That footage is from season 1, the pilot episode "The Wedsworth-Townsend Act", during the factory fire at the start of that episode.
Other mistake: When all the guys are asleep in the dorm, at 12:47 AM the dispatcher drops tones for Squad 51 and we hear him say, "Squad 51, person sick," yet the footage that is shown is of all the guys getting up, not just Roy and Johnny, putting on their turnouts.
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.