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.
Daisy's Pick Blind Date - S4-E7
Continuity mistake: While Roy, Johnny, and Cap are in the ice house with the hypothermic victim, there's a closeup of the pipe's frozen shut-off valve in the upright position with an ammonia leak, and the manifold temp/pressure gauges that are hanging from it. Then, when Johnny goes to wrap the rag around the valve it's upside-down, but in the next shot the valve is upright once again, and the manifold gauges are now facing the opposite way.
Daisy's Pick Blind Date - S4-E7
Visible crew/equipment: After the hypothermic victim is rescued from the ice house, just as the attendants wheel the stretcher into the ER, at the end of the hallway, the top of the set is visible where the ceiling should be.
Visible crew/equipment: While Roy is hanging off the side of the building with the second victim, Johnny's trying to tie off the swaying sign, then after he asks for some slack the second time, there's an overhead shot from the roof, and we can see the shadow of the camera and a bit of a crew member, at the bottom of the screen. Then a few shots later, from the same POV, we still see the camera's shadow, and we also see the leg of a crew member (white sneaker and dark pants) walk into the shot and back out, at the left of the screen.
Continuity mistake: When 51's guys get to the roof of the building with the swaying sign, Marco places the silver hose roller on the roof edge, but when Captain Stanley and Stevie's father lean over the edge to talk to Stevie, the second larger hose roller is already in place near the silver hose roller, even though the second one hasn't been brought to the roof yet by Engine 95's guys.
Continuity mistake: Just after Brackett tells Early that the patient he was talking to is his father, it cuts to a shot of Squad 51 pulling up the driveway, and the Engine 51 we see parked in the apparatus bay is not the current Ward LaFrance pumper, it's the original Crown engine from seasons 1 and 2.
It's How You Play the Game - S4-E19
Visible crew/equipment: At the scene of the traffic accident, when the injured driver starts shouting just before they load the stretcher onto the ambulance, a ducking crew member's head dips into view at the bottom, right corner of the screen.
It's How You Play the Game - S4-E19
Visible crew/equipment: After John is punched in the nose at the scene of the traffic accident, when the ambulance arrives the reflection of set lighting is visible on the surface of the ambulance.
Visible crew/equipment: After Station 51 is dispatched to the plane in trouble, just as Engine 51 makes the right turn into the lot, before they park beside the squad, a crew member's/cameraman's sleeve gets into the shot, at the left of the screen.
Visible crew/equipment: When Johnny and Roy are at the top of the open drawbridge, beside the car hanging over the edge, just after Roy says "Be careful, this could go at any minute," the moving shadows of the cameraman and another crew member are visible on the bridge surface. That shadow is visible in two other previous shots from the same angle.
Visible crew/equipment: After Station 51 is dispatched to the bomb threat, when the squad and engine pull into the alley, just as Roy stops the squad, the reflection of the cameraman/camera are visible in the spotlight's chrome surface.
Visible crew/equipment: When Station 51 is dispatched to a man trapped at World Picture Studios, just after they pass the studio's gate, in the moving shot from the left side of Squad 51, the reflection of the cameraman is visible on the lightbar atop the squad's roof.
Visible crew/equipment: After the fake eye exam 51's guys are sitting around the kitchen table, and when Chet tells them that he was sitting in the front row at the movies, there are moving shadows at the bottom, right corner of the screen, which do not belong to the guys.
Continuity mistake: When 51's guys are at the table eating and discussing Roy and Johnny's deal, Johnny tosses his car keys to Roy, and in the following shots those keys vanish and reappear on the table repeatedly, and in the shots where the keys appear on the table, it's the ketchup, mustard, and napkins that have vanished. Also notice that the ketchup's brand name is covered.
Deliberate mistake: When O'Brien shows up at the nurses' station for Dixie's answer, after she declines the offer Dixie walks off to a patient who's brought in by the police, and the last closeup that's shown of O'Brien is flipped - note his hair is parted the opposite way and the background is backwards.
Visible crew/equipment: When Roy and Johnny enter stage 3 to search for both Vic and the bear, just after Johnny and Roy split up, as the camera moves forward in Johnny's direction, the moving shadow of the cameraman/camera are visible on the filing drawers, to the left.
Visible crew/equipment: After Squad 51 is dispatched to a man injured at the movie studio, just as they reach the studio, in the shot from the back of the squad, the reflection of cameraman is visible on the lightbar atop the squad.
Continuity mistake: While Johnny is trying to reach the man who fell over the cliff, the bicycle falls all the way to the bottom of the canyon, and then there's a shot of the man and we can see that the bicycle is still above him at the side of the cliff, just before Chet says over the HT, "Lower him, Cap, the victim's broken loose."
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.