Nurse's Wild - S1-E7
Visible crew/equipment: When Roy and Johnny are at the house with the unconscious woman and barking dog, the set lights are reflected in the deputy's helmet.
Visible crew/equipment: When the truck driver who felt like his head exploded is in the treatment room with Early, Brackett and Dix, as the camera passes behind Brackett it casts a moving shadow along the two walls.
Visible crew/equipment: When Roy walks into the ER with the man who attempted suicide three ways, due to the low angle of the camera we can see part of the unfinished ceiling of the ER set, near the nurses' station.
Visible crew/equipment: On site at the construction accident, when the man with the back injury is lying in the stokes and being lowered with the ladder, a crew member/cameraman is visible on the landing at the lower right side of the screen.
Visible crew/equipment: When Early and Dixie are in the treatment room with Jenny, after Early asks Jenny if she can move her legs, the moving shadow of the boom and mic are visible on the wall behind Dixie.
Visible crew/equipment: At the scene of Paula's traffic accident, when Captain Hammer stands in Engine 51's cab and tells Marco to get the reel line, the reflection of equipment and set lighting are visible in the chrome surface of driver's side spotlight.
The Lighter-Than-Air Man - S5-E8
Visible crew/equipment: At the scene of the bride and groom's traffic accident, when Johnny asks Crockett if he ever thought about a career as a marriage counselor, the outline of the lav mic transmitter is visible on the front of Johnny's shirt.
Visible crew/equipment: After Chet falls through the roof at the structure fire, when Truck 3 raises their ladder, we can see the cameraman/camera's shadow just as the ladder reaches the roof.
Pressure 165 - S5-E7
Visible crew/equipment: When Station 51 is dispatched to the structure fire at the flour company, while en route there's a closeup of Squad 51, and the reflection of the filming vehicle can be seen in the spotlight.
Visible crew/equipment: When the man, who walked in with his daughter, has a heart attack at Station 51, while he's lying on the floor in the apparatus bay we can see the top of the set, the part of the ceiling that's incomplete.
Visible crew/equipment: After the ambulance transporting the cardiac victim is involved in a traffic accident, when Roy contacts the dispatcher about the accident, the reflection of location set lighting is visible on the back window of the ambulance.
Visible crew/equipment: After everyone worked together on the cardiac arrest while the visiting administrators watched, at the nurses' station, when Johnny pours the coffee for himself, which Roy promptly takes, the reflection of set lights and equipment are visible in the very reflective chrome coffee pot.
It's How You Play the Game - S4-E19
Visible crew/equipment: When Squad 51 is en route to the car salesman who was bitten by a tiger, just before the squad turns into the car lot, the reflection of the filming vehicle is visible in the squad's spotlight.
Visible crew/equipment: After Station 51 rescues the novelist from his attempted suicide, when John accompanies the stretcher into the ER, the outlines of the mic transmitter and wire are visible on the back of his shirt.
Visible crew/equipment: When John and Roy tackle the hallucinating veteran, the outlines of the mic transmitter and wire are visible on the back of Johnny's shirt. As an aside, this scene was shot right outside Universal Studios, note the Black Tower/MCA Tower (which houses Universal's execs) when John tells the veteran that it's not a trick and to calm down.
Visible crew/equipment: When Roy and Johnny are with the guy who skateboarded and fell into the cactus bush, the outline of the mic transmitter is visible on Johnny's right side.
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.
Visible crew/equipment: When the guys are at the gas station with the broken pump nozzle, after Marco and the stretcher are loaded onto the ambulance, the reflection of the location array lighting can be seen on the back of the ambulance, when Johnny shuts its doors.
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.