Visible crew/equipment: After Johnny and Roy save the man at Vic's party, when they are leaving, the reflections of crew members and production equipment are visible on the orange surface of the ambulance as it drives away.
Revealing mistake: At the apartment complex where the jet fighter had crashed there's an explosion, and when one of the firefighters becomes engulfed in flames his helmet falls off, and the special fireproof headpiece that the stuntman is wearing is visible.
Visible crew/equipment: Just after Herbert leaves the station in the morning, dispatch sounds the alarms, and when Roy and John are in the squad while the dispatcher begins talking, there are nice reflections of the camera, reflector screen (in the background), and crew members/cameraman who move around, that are visible on the surface of the spotlight. Additionally, the shadow of the boom/mic is perfectly visible on the windshield as it moves down.
Revealing mistake: When Squad 51 leaves Rampart, in the first interior shot facing Roy as John says, "Yeah, I'll tell ya, when it hits ya... Boy when I met Valerie it hit me," through the back window we can see movement at the back of the squad. But in the shot facing Roy when John says, "So that's that... That's exactly how it is," through that back window we can actually see a crew member's face (sideways), who has a mustache, right behind John's head, as he's riding on the back of the moving squad. It's so funny, have a look.
Continuity mistake: When Johnny is writing the 'for sale' sign about his Land Rover, in the wide shot the two phone numbers begin with "853" and "352", but in the closeup a piece of paper has been glued over the phone numbers, and the new numbers now begin with "321" and "749."
Continuity mistake: When Brackett asks Early and Morton to assist with the examination of the hallucinating veteran, in the shot from the hallway the doctors walk into treatment 1, its door has no window, but when it cuts to the shot from inside the room, its door has a window, which means they're all in treatment 2 or 3, not 1.
Visible crew/equipment: When Roy and Johnny climb up the open drawbridge, just as they reach the top and see the car dangling off the edge, when Roy says "Boy," the second cameraman is visible behind Roy sitting on the bridge.
Continuity mistake: When Johnny and Roy are heading to the parade in The Old Engine, and get sidetracked dealing with a fire rescue, they are wearing the old-style shirts with a ten-button, square bottom bib front, with five buttons on each side. When Captain Stanley laughs at them on the roof, their shirt style differs in the close-up, it's now a nine-button, pointy bottom bib, with four buttons on each side and one button at the bottom point.
Continuity mistake: While Johnny, Roy, and Vic try to outrun Charlene inside Stage 3, after heading down the ladder, when Roy opens the door to find Charlene standing there, Johnny's holding the red extinguisher in his right hand and the nozzle in his left hand, but next shot they've switched hands.
Visible crew/equipment: When the guys wake up in the morning and walk into the kitchen, the clear reflection of the camera dolly is visible on the oven glass door as it trucks to the right, when the guys see the empty mouse trap.
Visible crew/equipment: When Station 51 is on scene at the vehicle accident in the canyon, after Marco uses a crowbar to free the driver of the station wagon and he pulls the driver out, a crew member standing behind the FX 6-ft wind machine fan (to blow smoke) are visible in the background beside the other overturned car. As an aside, in the previous and following shots that crew member and wind machine fan are in the same spot where Chet and Johnny supposedly are.
Continuity mistake: When Roy and John are talking to Vic at his party, his manager's cigar changes length repeatedly, from short to long and back again, depending on the camera angle.
I'll Fix It - S4-E2
Continuity mistake: When Station 51 is at the scene of the oil well eruption, underneath a house which was built atop an abandoned oil field, just after Johnny tells Roy that he thinks the whole foundation is slipping, it cuts to a shot of the front porch as one of the porch columns (and part of another) breaks and falls. However, when the guys finally free the trapped man and carry him out, all the columns are upright once again.
Visible crew/equipment: When Roy and Johnny are trying to get the basketball player (Kareem Abdul-Jabbar) out of the car, and when Roy exits the car to get equipment, the outlines of the mic transmitters and wires are visible on the back, left side of Johnny's shirt, and back, right side of Roy's shirt.
Visible crew/equipment: When Art, The Screenwriter, goes on his first ride-along with Squad 51, just as Art rambles on about the fire truck on its mission of mercy going 80 miles an hour, two shadows of mic/camera equipment are visible on the left and right side of Squad 51's hood. What's amusing is that a moment prior to this, Art actually says that they could mount a camera right on the hood of the truck, when they make the film about paramedics.
Daisy's Pick Blind Date - S4-E7
Visible crew/equipment: When Roy and Johnny are with the hypothermic refrigeration engineer, the outlines of the mic transmitter and wire are visible on the back, left side of Johnny's shirt. Note that when Johnny and Roy are in the ambulance with the patient, Johnny is not wearing the lavalier transmitter and wire anymore.
Continuity mistake: When Brackett tells Dixie about the visiting administrators she's holding a clipboard, but when she's stopped by the man whose son has an arm injury, Dixie's now holding a brown folder.
Continuity mistake: After Johnny and the attendants exit the ambulance with Dora, the pregnant woman, the ambulance is empty and the drug box is on the seat with the Biophone on the floor beside the seat, but in the next shot as the gurney is wheeled inside, the drug box is now on the floor between the Biophone and seat.
Continuity mistake: When 51's guys go down into the tank to try and subdue Al, the big guy who has a chemically induced psychosis, the ring Al was wearing on his left hand in the overhead shots is gone, but when Al shakes Chet upside-down in the closeups the large ring is back, but then it vanishes again.
Continuity mistake: The window from which the sniper is firing sustains damage with broken glass panes, but then the glass panes are whole and intact, and then they are broken again.
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.