The Wedsworth-Townsend Act - S1-E1
Other mistake: When Squad 10 is dispatched to the the high-voltage electrocution, Tony opens the bay door, but the closeup we see is actually the same closeup of the hand cupping the switchplate that was shown earlier, when dispatched to the nighttime factory fire.
An Ounce of Prevention - S6-E13
Continuity mistake: At the ferris wheel, when the boy starts to climb down to help the man in the lower seat, in the closeup he steps on the two yellow, fluorescent tube light bulbs causing the bulbs to plummet and shatter on the ground below. The problem is that those two fluorescent bulbs did not even exist in the prior wide shots, that lamp socket space was empty.
Visible crew/equipment: When Johnny chases Harriet down the street, behind Johnny we see Roy backing up the squad to follow them, with nobody around, then when it cuts to the view from within the squad, the reflection of crew is visible in the driver's side mirror.
Visible crew/equipment: When Roy gets the little girl, Angie, out of the wrecked airplane and then places her in the Stokes basket, the outlines of the mic transmitter and wire are visible on the back of his shirt.
Visible crew/equipment: When Brackett, Dixie and Early are working on the unconscious little boy, once Brackett says to go with the pacemaker, multiple black T-marks are visible all over the floor - three under the gurney and one near the cart. Another actor's white tape mark is visible under the gurney (partially blocked by the green oxygen tank), where both Early and Dixie stand at different times.
Fair Fight - S6-E5
Visible crew/equipment: After the cave-in rescue, when Dixie, DeSoto and Gage are in the ER, Gage washes his face and as he comments that he wasn't cut out to be a mole, two tape marks are visible at his feet.
Visible crew/equipment: When Mr. Grady (self-defense instructor) is in the ER, being examined by Dr. Brackett, there is a visible T-mark on the floor behind Gage.
Visible crew/equipment: After Chet is brought to the ER, Gage goes to the nurses' station. When Brackett opens the door and walks out of the base station booth, the actor's T-mark is visible on the floor behind him.
Greatest Rescues of Emergency - S7-E5
Other mistake: As the men are receiving their new badges and the chief congratulates them, he calls Craig Brice. The Brice that accepts the new rank is a black man. In all previous episodes, Brice is white.
Visible crew/equipment: When Brackett's helicopter takes off the filming helicopter can be seen through the window. (00:03:45)
Continuity mistake: Just before the opening credits both Engine 51 and Squad 51 are inside the station. The alarm goes off and when Squad 51 leaves the station Engine 51 has vanished.
Daisy's Pick Blind Date - S4-E7
Other mistake: When Squad 51 is dispatched to "man needs assistance", in the exterior shot as the squad rolls out of the apparatus bay we can see Engine 51 still inside the bay, but the real Station 127's engine is parked right beside the station house.
Continuity mistake: When Roy and Johnny are on the roof with Harriet, we can see the shadow being cast by the utility pole on the street down below, and when the police car shows up moments later that shadow has changed significantly. (00:12:40)
Visible crew/equipment: When squad 51 parks upon arrival at the gas station the array lighting is visible on the driver's door.
Continuity mistake: After Johnny and Roy bring the injured fireman to the ER, Emma walks up to them in the hallway to ask why they haven't put out the fire yet, and the large handbag hanging from her left arm is suddenly on her right arm when it cuts to the close-up.
Continuity mistake: While Brackett is with Ken in the ER he's wearing a blue/white striped tie, and when he calls Ken's doctor the tie is tied differently, but then it's tied the original way.
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.
How Green Was My Thumb? - S3-E17
Character mistake: When Johnny is filling the radiator on the squad, he pays close attention to not over fill. After Chet comes in and asks a question to Roy, the alarm goes off, Johnny closes the squad hood, without pulling the radiator cap on.
Greatest Rescues of Emergency - S7-E5
Other mistake: After getting their promotions, Roy and Johnny start recalling their history together and when Johnny remembers joining the paramedic program he says he was at 8's, but Johnny was at 10's and it even shows the clip from the show's pilot where Johnny's standing behind Engine 10 talking with his Battalion Chief. The filming of the show's Station 10 was done at the real Station 8. As an aside, the real Station 8 was also seen in the 1950's TV show Rescue 8.
Continuity mistake: In the opening scene when Johnny and Roy walk into Captain Stanley's office, Johnny's pack of cigarettes is in his right shirt pocket. As he and Roy are talking in the apparatus bay, the cigarettes are still in his right shirt pocket. When Johnny enters the kitchen after Roy, the cigarette pack has magically moved to his left shirt pocket.
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.