Continuity mistake: After Roy and Johnny's pre-dawn rescue at the market, by the time Roy advises dispatch about the tiger and when Animal Control shows up at the market, it's already past sunrise, but when Les and the officer walk into the store and then when they follow the tiger up onto the roof, it's nighttime again.
Other mistake: When Engine 51 pulls up to the hotel with the injured man dangling from the hotel sign, Captain Stanley addresses Chet and says, "Chet, Roy and John'll need a line," but the subtitles read, "See that? Roy and Dan'll need a line, " even though there isn't anyone named Dan. Subtitles from Universal Studios 2010 DVD.
Other mistake: When the tones drop and Station 51 is dispatched to a "man injured", there is a closeup of the guys running from the kitchen into the apparatus bay, heading for the squad and engine, and none of them are actually 51's guys.
Other mistake: During the fire at the chemical plant, when Captain Stanley and Roy find the missing man and carry him out, the subtitles read that Johnny says "All right, grab his feet," when in fact it's Captain Stanley who says that - Johnny's not even in the same room with them. Subtitles from Universal Studios 2010 DVD.
Smoke Eater - S4-E16
Continuity mistake: When Station 51 is dispatched to the structure fire including a chemical lab, Johnny and Roy put on SCBA tanks with distinctive markings/stickers before going in, but those tanks change while inside and when they exit with the victims of chemical smoke inhalation.
Revealing mistake: When Johnny, Roy, Vince, and the wounded officer are hiding between the bakery truck and car, before the multiple bullet holes actually appear on the side of the truck, those areas where the holes will show up have off-color markings, prepared for the stunt.
Continuity mistake: While on the way to the parade in The Old Engine, when Johnny and Roy deal with the fire rescue and reach the roof, Johnny has a rope bundle swung across from his left shoulder to his right hip. However, in the next shot as they run across the roof, the bundle is now swung from his right shoulder to left hip, and the rope is also bundled differently.
Visible crew/equipment: When the doctor shows up at the house of the man who kicked in his TV, as the camera moves back, the top of equipment (presumably the boom mic) is visible and moving in the reflection of the mirror on the wall.
Visible crew/equipment: When Johnny and Roy are working on the man who is unconscious due to electric shock, the bulging outlines of the lavalier mic transmitter and wire are visible on the back left side of Johnny's shirt.
Visible crew/equipment: When Roy and Johnny are at the laundromat with the drunk man, the bulging outline of the mic transmitter is visible on the left side of Johnny's shirt, over his belt.
Continuity mistake: When Roy and Johnny get back to the station, Johnny asks Chet about the condition of the house after the fire, and in the wide shot Johnny has a really red pimple near his chin, but in his closeup the pimple has vanished, only to reappear in the next shot.
Visible crew/equipment: When Charlie, who has smoke inhalation, is placed on the gurney in the treatment room, the actor's white tape mark is visible on the floor, where the nurse stands in a moment.
Continuity mistake: During the house fire, when Chet kicks the door twice he leaves dark marks on the door, but when he kicks the door a third time the marks on the door have vanished.
Camera Bug - S4-E10
Visible crew/equipment: At the accident scene with the truck carrying dynamite, when Roy is leaning over the driver's door, the outline of the mic transmitter is visible on the back, right side of his shirt. Then, when they're carrying the driver to the top, Johnny's becomes visible at his left side.
Camera Bug - S4-E10
Visible crew/equipment: When Johnny is driving Roy nuts by taking closeup pictures of him checking the squad's engine, the outline of the lavalier mic wire is visible on Johnny's back.
Camera Bug - S4-E10
Visible crew/equipment: At the school fire, when Johnny is administering the O2 to the teenager with smoke inhalation, the bulging outlines of the mic transmitter and wire are visible on the back, left side of Johnny's shirt.
Visible crew/equipment: When all the guys are talking to Mr. Gibson, who is stuck in the trench he fell into, the outlines of the lav mic transmitters are visible on the backs of Roy's and Johnny's shirts.
Continuity mistake: When Dr. Morton leaves the room of the patient who attempted suicide to get Jack, he takes the pill bottle from Dr. Early, carries the medical chart holder, and is wearing a stethoscope around his neck, but in the hallway when he gets Jack the pill bottle and chart holder are gone, and the stethoscope is in his pocket. Then, when they walk back into the room, Morton's holding the bottle and chart holder, and the stethoscope is back around his neck.
It's How You Play the Game - S4-E19
Continuity mistake: When Johnny is in the ambulance with the car salesman that was bitten by the tiger, Johnny opens the man's shirt, but does not remove his western tie scarf. However, in the man's closeup the tie is open with the scarf slide removed, and then it's back to being tied with the slide.
It's How You Play the Game - S4-E19
Visible crew/equipment: When Roy and Johnny are on scene at the car accident, the bulging outlines of their mic transmitters and wires are visible on the left sides (above the belts) of their shirts.
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.