Continuity mistake: After Chet sees The Mouse run under the fridge, when the guys are discussing The Mouse Johnny's medical holster is clipped at his right hip, but when they're dispatched to 'man unconscious at laundromat' his medical holster is now at his left hip as he walks to the squad.
Visible crew/equipment: When Station 51 is dispatched to the structure fire, just as Engine 51 rolls out of the apparatus bay, the reflections of the location shoot's array lighting and two reflector screens are visible on the side of the engine.
Continuity mistake: During the house fire, Marco's holding the hose behind Chet, while Chet is kicking open the front door just before it flashes, but in the next shot both Chet and Marco are manning the hose when the fire flashes, knocking them down the stairs.
Continuity mistake: At the apartment complex fire, after Truck 82 sets its outriggers, Engine 28 is right behind them with their supply line and duals laid out, but quite a few shots later Engine 28 is just pulling up behind 82, even though they were already there all set up.
Visible crew/equipment: At the start, when dispatch interrupts the mannequin practice with a structure fire, after the shot of Mike getting into his turnout, as Engine 51 rolls out of the apparatus bay, the reflection of array set lighting and two reflector screens are visible on the moving engine.
Continuity mistake: During the fire at the apartment complex, when Cap talks to dispatch over the HT and requests a second alarm, we see Roy put up that first ladder, but after the Pasadena engine arrives, Roy's just putting up that first ladder. Second, after Engine 82 extends their outriggers, it cuts to the flames and we see that three ladders are already against the building, but then there are only two up - the third will go up a few shots later (when Roy reaches the balcony) Third, we see Roy start climbing the ladder that's farther from the camera (the one Johnny's holding), but when Roy reaches the balcony, he's climbing up the ladder that's closer to the camera.
Continuity mistake: When Station 51 is dispatched to 'plane crash into a structure' the address is given as 1145 Delmar Drive, but when they arrive at the apartment complex, the 3-storey structure's address is 775.
Continuity mistake: When Herbert is leaving the station, there are shots of him on the left edge of the bay doorway, but in the shots of the guys looking at Herbert, particularly Chet and Marco who are standing in front of the squad, it's as if Herbert is crawling around towards the center of the bay doorway - their eye contact is way off.
Visible crew/equipment: After Squad 51 responds to the 'man unconscious' at the laundromat, while they're en route, when Engine 36 contacts them that the man is in full arrest, the reflection of the vehicle with the camera is visible on the spotlight.
Visible crew/equipment: After Chet tells the guys that they have to get rid of The Mouse, when he says "You don't understand, these things are like rabbits," the moving shadow of equipment, probably the boom mic, is visible on the top cabinet behind Chet.
Visible crew/equipment: After the guys decide to eat lunch before resuming their CPR practice, when Chet picks up the CPR mannequin and walks toward the fridge, the top of the set is visible at the corner, between the fridge and the stove. We can see the top of the set again later, after Chet picks the losing matchstick and has to set the mousetrap himself.
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.