Continuity mistake: At the start, Station 51 and Truck 8 are dispatched to the cardiac patient stuck in the elevator, and we even see Truck 8 roll up in front of the building in the overhead exterior shot, but in the hotel it's 127's guys with 51's.
Captain Hook - S6-E8
Other mistake: While Roy, John, and Chet are talking about the party, and how emotional it all was, we hear Hookrader say, "Lopez," just as he walks into the kitchen where Marco Lopez is sitting, but the subtitles read, "Hello, guys."
Captain Hook - S6-E8
Other mistake: When Johnny and Roy rappel down the cliff to the downed police traffic helicopter, Johnny gets on the HT and says, "All right, Cap, this is HT 51..." but the subtitles actually read, "Hi, Cap, this is HE 51..." Then when they reach the chopper, Johnny says, "There it goes," and Roy says, "Okay, I'll take this side," but the subtitles reverse who says both lines. Subtitles from Universal Studios 2010 DVD.
Captain Hook - S6-E8
Visible crew/equipment: After Station 51 is dispatched to "aircraft down," just as the squad and engine roll up on the scene, the reflection of the camera crane can be seen on Engine 51's windshield.
Peace Pipe - S2-E5
Other mistake: When John and Roy are up on the scaffold with the injured man during the sniper fire, from the time they unfurl the large tarp and tie it off to the beams the sniper fires zero shots at them, zip, but later at the station Chet asks John, in all seriousness, if he got a good look at the tarp before they left, and tells him that the tarp looked like Swiss cheese due to the sniper fire.
Other mistake: When Brackett asks Early to see the patient (Jaime Farr) who claims he can't move his arm because of a curse, Early walks into treatment 5, but in the shot from inside the room we can see that they're in treatment 2.
Other mistake: When Roy and Johnny are with the woman whose hand is caught in the mixer, we can see tape on the side of the stand mixer (Sunbeam) as well on the food containers, covering all their brand names.
Other mistake: Jamie Farr appears in 2x19 "Boot" as Alan Austen, the guy who claims that he can't move his arm because of a curse, but he's mistakenly listed in the credits at the end of this episode.
Continuity mistake: When Roy and John are at the inexperienced cook's apartment the second time, when her fingers are caught in the mixer, she's wearing a blue/white striped dress and a watch on her left wrist, but in the closeup as she reaches for the boiling pot her watch is gone and it's a white sleeve on her arm.
Other mistake: On the first run of the Ward LaFrance we hear the dispatcher say, "Wrecking yard fire," but subtitles read, "Working yard fire," and as soon as Engine 51 rolls up on scene Mike turns to Captain Stanley and asks, "Light water?" but subtitles read, "Do we got water?" Then we hear the dispatcher say, "Repair 3, call Station 8," but subtitles read "Return 3..." Subtitles from Universal Studios 2010 DVD.
Other mistake: On scene at the plane crash, just as Roy and John are about to head down to the aircraft we hear the dispatcher ask, "Foam 23, what is your location?" but the odd subtitles read, "Phone 23..." Subtitles from Universal Studios 2010 DVD.
School Days - S2-E14
Continuity mistake: Before the housekeeper leaves the library to open the door for 51's guys, we see Dr. Temple pinned under the bookcase and two red armchairs in front of the fireplace, but when she returns to the room with everyone following her one of those armchairs has vanished.
The Promise - S3-E11
Visible crew/equipment: After Squad 51 is dispatched to 'woman down', just as the squad rolls up in front of the apartment building we can see a bit of the camera's production equipment at the bottom left corner of the screen, which is then pulled quickly out of shot.
How Green Was My Thumb? - S3-E17
Other mistake: Eric Shea appears in "The Hard Hours" as Clyde, the boy who built a full size rocket, but he's mistakenly listed in the credits at the end of this episode.
Other mistake: When Johnny and Roy are with the baby who's sleeping in the back seat of the locked car John says, "The roof is hot, I think the heat might have built up inside," and the bystander says, "Lord knows how long he's been lying in there broiling in the sun," but what's funny is that they're all wearing winter coats and jackets.
How Green Was My Thumb? - S3-E17
Other mistake: During the refinery fire, while Roy is with Fernando the first victim, we hear Roy say, "It's OK, you're gonna be all right," but the subtitles read that Johnny says that. Subtitles from Universal Studios 2010 DVD.
How Green Was My Thumb? - S3-E17
Visible crew/equipment: Just as Roy opens the door to Mrs. Johnson's apartment and he and Johnny walk in, the shadow of production equipment (looks like a reflector screen on a tripod) is visible on the wall behind them.
Other mistake: After Engine 51 and Squad 51 are dispatched to "man trapped," while en route to the incident Engine 86 becomes available, so when the dispatcher cancels Engine 51 we hear Captain Stanley respond, "Engine 51," but the subtitles read that Johnny is the one who responds "Engine 51," which is pretty silly since John and Roy are in Squad 51. Subtitles from Universal Studios 2010 DVD.
Other mistake: At The Boat explosion incident, when Roy and Johnny climb aboard The Boat Johnny says, "We'll set up the Biophone here," but subtitles read "We'll set up the platform here." Subtitles from Universal Studios 2010 DVD.
Continuity mistake: After 51's guys rescue the man from under the fallen engine, when the ambulance leaves we can see only the name Mayfair is printed on its side, but en route to Rampart and when Roy has the ambulance stop and then go, there's a red cross printed on the surface above Mayfair.
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.