Visible crew/equipment: During the structure fire, in the shot after Johnny runs up the ladder to the roof to get to Captain Harmell, a crouching crew member can be seen under the open passenger side door of Engine 17.
Revealing mistake: At the structure fire, when Engine 9 and Engine 17 roll up, we can see the large, red, rectangular vinyl material that is adhered to the front of the engines, with their company numbers printed on it. Additionally, the red vinyl material adhered to the top of 9's and 17's cabs, which cover their real company numbers, flap up in the wind.
Continuity mistake: At the construction site, after the younger patient has been taken to the ambulance, when Roy tells Johnny that it was pretty good radio work, Johnny's holding his helmet, but in the next shot as Johnny stands up his helmet is gone, though there is a helmet near the drug box behind him.
Audio problem: When Roy and Johnny are with Dixie in the ER, after all the bikers' violence, Squad 51 is dispatched to 'man possibly trapped' and when we hear Johnny respond, "Squad 51, affirmative," his mouth does not say the word "affirmative", he says something else.
Heavyweight - S3-E5
Character mistake: When Johnny first contacts Rampart via landline about the stabbing victim, while Roy is across the street with the gunshot victim, Brackett gets on the line and asks Johnny if he started an IV, to which Johnny replies no, then he asks what the vitals are. Johnny has only just made contact with Brackett about this patient, so Johnny could not have started an IV without the doctor's consent, Brackett knows this. This goes against established procedure.
Heavyweight - S3-E5
Visible crew/equipment: When Roy and Johnny are with the man who was injured by a gunshot, Johnny goes across the street to treat the stabbing victim, and just as Johnny and the others enter the living room, the shadow of the moving boom is visible on the wall to the right.
Continuity mistake: After the woman has staggered into the ER she is seated in the wheelchair, and when she jumps out of the wheelchair there is a tall ashtray can behind her beside the wall, but in the next shot that tall ashtray can has vanished.
Propinquity - S3-E20
Visible crew/equipment: When the ambulance that Roy is riding in is involved in a traffic accident, the ambulance driver, Hal, comes out to help, and the outline of the mic transmitter is visible on the back of Hal's white shirt.
Continuity mistake: After Station 51 is dispatched to the fire/explosion at the chemical company, when John heads inside to rescue the chemist, the SCBA cylinder he's wearing has one white sticker and one pinkish sticker. By the time John brings the victim out to the sidewalk, his air tank has changed back and forth repeatedly to one that has two red stickers.
Visible crew/equipment: Just before the hermit leaves Rampart, the actor's mark is visible on the floor in front of the market owner's feet, and when Dixie turns the hermit's wheelchair, the tape mark in front of Brackett becomes visible.
Visible crew/equipment: When John and Roy get back to the station, Captain Stanley asks them to step into the office, and as Cap walks through the doorway the camera's shadow is visible on the wall at the left. Also note the coiled electrical wire lying on the floor in front of the squad, and the shadow of something that is directly in front of the squad, even though the squad just rolled in.
Continuity mistake: When Roy and Johnny get back to the brush fire's base camp, they join the rest of 51's guys who are sitting and eating. During this entire scene, continuity between shots is off. Chet's coffee keeps switching from Johnny's hand to being on the ground, and then between both of Chet's hands to being on the ground. Also, the bread on Chet's sandwich is either white or a darker type, the sandwich size varies, and it also changes hands.
Revealing mistake: When Station 51 is dispatched to the chimney explosion, en route there is a moving bird's-eye view as the filming chopper follows 51's vehicles making a right turn. On the ground below, there are two people standing beside a blue station wagon, and one points up to the chopper flying overhead.
Visible crew/equipment: After Station 51 is dispatched to the bulldozer accident, just before Engine 51 comes to a stop at the junkyard there's a shot from the perspective of Engine 51's roof, with the Beacon Ray dome light in front, and on the light's red and chrome surface we can see the reflection of the camera mounted on the roof behind the dome light.
Continuity mistake: When Roy and John are in the ER's staff lounge discussing Donaldson, Roy's button, second from the top, is buttoned up in the wide shots, but is unbuttoned in his closeups during the conversation.
How Green Was My Thumb? - S3-E17
Visible crew/equipment: When John and Roy are searching for the missing man during the fire at the winery, a flaming piece of debris falls in front of Roy. When Roy climbs up to the deck above him, it cuts to Roy on his knees about to stand up, and we can see someone moving right near him, at the left of the screen, even though he's alone.
How Green Was My Thumb? - S3-E17
Continuity mistake: When Johnny and Roy visit Mrs. Johnson on the 6th floor, they take the elevator near the nurses' station, at the south end of the ER wing, and when they exit the elevator they turn left to room 603. This is completely impossible considering the actual floor plan of the hospital, since in all the exterior shots of the ER it is only 2-storeys.
Continuity mistake: When Roy and Johnny are with the man in full arrest on the tower at the refinery, Johnny hooks up the Datascope with the wire, but in all the overhead shots there is no wire at the back of the Datascope monitor.
Visible crew/equipment: After the boy who ingested the ant poison is loaded onto the ambulance, when the back doors are shut, the reflection of the location set lighting is visible in the ambulance window and on its surface.
Visible crew/equipment: After Johnny carries Cindy down from the treehouse, when Cindy's mother joins them, the bulging outline of the lavalier mic transmitter is visible on the back of her white sweater.
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.