Continuity mistake: When Johnny, Roy, and Captain Stanley are rescuing the people trapped inside Olive View Hospital, they are wearing distinctively marked SCBA tanks on their backs, and when all three firemen exit the doorway, Cap is wearing an entirely different tank, and the tanks that Johnny and Roy are wearing have been switched. Then when Johnny jumps off Engine 82, his tank differs again, and when he walks over to the Battalion Chief it's changed yet again.
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 Johnny and Roy are in the ER after the cave-in rescue, while they're talking to Dixie and Brackett, we can see how long Johnny's hair is. After they get back to the station, when the guys decide to name the dog Henry, there's a closeup of Johnny and now his hair is much shorter and even layered at the sides. Additionally, the dirty areas on his shirt change.
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.
Continuity mistake: After Squad 51 is dispatched to the 'injured man', when Roy and Johnny get out of the squad, Roy is not wearing his watch as they're walking to the victim while getting hounded by the dog, but in the next shot the watch is back on Roy's wrist as the dog chews on his pants.
Continuity mistake: During the fire at Rampart's lab building 8K, when Roy and Johnny are placing the salvage covers on important records, Johnny is wearing the SCBA tank with the two red stickers and Roy's tank has a large arrow sticker, but when they exit the building their tanks have switched.
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: When Dixie shows Johnny the newspaper, Johnny reads the ad aloud which states, "Wanted, 1925 Paige fire truck, $25,000, if in mint condition," and Johnny says that it is exactly what the ad submitter wants. The "it" being Roy and Johnny's refurbished fire truck. The problem is that in 3x2, "The Old Engine," when Johnny and Roy are telling Chet and Marco about their purchase, Johnny says that it's a 1932 Dennis, and when they're looking it over, the blue "Dennis" emblem is attached to the hood of the engine.
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.
Continuity mistake: When the patients who were treated at 86's arrive at the ER, Dix has Morton take the asthmatic boy with bronchitis into treatment 1. Then, when Roy is with Early in treatment 4, Early tells Roy to go to treatment 1 to ask Morton if he needs help, and when Roy walks into treatment 1 we can see that it's not really treatment 1, it's actually treatment 4 just playing the part of treatment 1.
Continuity mistake: When they pull the man with chest pains from the pickup truck, Dixie says treatment 3, which is opposite the receiving entrance and on the same side of the hall as the nurses' station, closest to the red line on the hallway floor, but when Dixie leaves the treatment room it's at the side of the hallway closest to the yellow line, and since there's a window on its door we know it's actually treatment 1 that he's in, not 3.
Continuity mistake: After Roy's had his arm bandaged in the ER, Brackett points to the treatment room Johnny's in and says he's in 4, and Roy heads there. Then after speaking to Johnny, when Roy opens the door to leave Johnny's treatment room, we can see the treatment room facing Johnny's, and it's treatment 2, which means that Johnny is actually in treatment 1, not 4. Plus the fact that the boy with the heart problem is supposed to be in treatment 1 at that time.
Continuity mistake: In the bookmaker's apartment, while Roy. John, Marco and Chet are working on the bookie who's in full cardiac arrest, Vince walks in and speaks to Captain Stanley. Then Vince, who's wearing a watch and ring on his right arm/hand, reaches for all the ringing telephones, and one by one he removes the receivers from the bases, but the right arm/hand in the closeup has no ring or watch.
Continuity mistake: When Johnny calls in to Rampart, Brackett answers and presses the two buttons to record the conversation, then tells Johnny to standby leaving the two buttons depressed, while the drunk driver is brought in. In the next shot, a closeup of Johnny, Brackett tells 51 to go ahead, and in the following shots Brackett continues to listen to Johnny, but none of the buttons are depressed on the tape machine to record the conversation. Then when Brackett gets off the line, he actually presses the tape machine's off button, as if the buttons had been depressed and the conversation recorded.
Continuity mistake: When Brackett asks Early to see the patient (Jamie Farr) who belongs to an occult group and has no function in his right arm, Brackett's wearing a blue/white striped tie, Early's wearing a red/blue striped tie, and Dixie's wearing a uniform dress. However, in the previous and following shots, Brackett's wearing a blue/red/gold patterned tie, Early's wearing a solid black tie, and Dixie's wearing a 2-pc nursing uniform with pants.
Continuity mistake: When Roy and Johnny cross the road to talk to the sheriff about the injured rock climbers, Roy does not have gloves in the back pocket of his jeans or anywhere else, nor does he take gloves from the sheriff's trunk with the other climbing gear, before he and Johnny begin their ascent. However, when he reaches the boys, Roy has a pair of thick work gloves sticking out of his back pocket.
Continuity mistake: When Johnny and Roy are at the apartment building with the broken elevator, Roy's watch is gone when they climb the steps, but he's wearing the watch when they enter the apartment, then it vanishes when they head back down. That watch reappears again, disappears and reappears until they go back up to the apartment for the second time.