Transition - S4-E15
Continuity mistake: After Gil and Johnny have lowered the man from the amusement park ride, Gil, who's wearing the backpack, rappels down first and reaches the ground. Then when Johnny hooks in and rappels down, there's a shot of what is supposed to be Johnny rappelling down, but it's actually a shot of Gil, because it was Gil who was wearing the backpack.
Continuity mistake: After Squad 51 gets back to the station, Roy and Johnny remain in the squad discussing Roy being the coach, and when the dispatcher drops the tones, we see a closeup of five pair of legs rushing out of the kitchen, even though we should only be seeing four pair of legs, since Roy and Johnny are already in the squad.
Revealing mistake: When Squad 51 gets back to the station, while Johnny's trying to convince Roy to coach their singing, the usually highly reflective chrome surface of the spotlights have been sprayed with a dulling spray, to temporarily dull the finish for this shot.
Camera Bug - S4-E10
Continuity mistake: After Roy and Johnny are dispatched to Station 68, Bob is lying on the floor with his shirt buttoned up and Roy has his hand on Bob's chest taking his respiration, but when it cuts to Bob's closeup his shirt is already unbuttoned, with the ECG electrode discs and leads in place on his chest. Additionally, in Bob's closeups the leads go from attached to the discs, to unattached, to attached again.
Revealing mistake: When Johnny and Roy are at the top of the open drawbridge, Johnny is wearing a watch on his left wrist, but when his stunt double rescues the woman in the car dangling off the edge, he is not wearing a watch. Additionally, the stuntman's pompier belt has a large axe sheath attached to it, but Johnny's life belt does not, and the stuntman's arms are much hairier, as usual.
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.
Continuity mistake: When Johnny and Roy are with the boy who is in anaphylactic shock from the bee sting, Johnny's watch reads 2:25, then 2:35, and then 2:25 again.
Transition - S4-E15
Visible crew/equipment: At the start of the episode, when Captain Stanley leans over to hang up the telephone and walks out of his office, the outlines of the lavalier mic transmitter and wire are visible on the back, left side of his shirt.
Visible crew/equipment: When John and Roy help the driver out of the overturned armored truck, the bulging outline of the mic transmitter is visible on the left side of the driver's shirt, and when Roy's arm is around the man's waist, Roy even puts his palm over the mic transmitter as he bends to pickup the man's gun.
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.
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.