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.
Visible crew/equipment: While John's trapped with the two men in the cave-in, he digs and finds the opening to the pipe, and when he starts shouting up to Roy, the cameraman's knee/leg is right beside John's left hand, at the lower right corner of the screen. It really is.
Visible crew/equipment: After Roy and Johnny get back to the station the other guys tell them to check the dog to see if he's sick, and when Roy checks Henry's pupils and Johnny checks his pulse, all the guys are standing behind Johnny and Roy., and we can see the shadows of crew movement in the kitchen at the top right corner of the screen.
Other mistake: When Squad 51 is dispatched to 'man with head injury' which is the fighting couple, the dispatcher says "10763 Riverton, cross street Valleyheart Drive," but when they arrive the two street signs at the intersection read "Valleyheart Drive 10700" and "Riverton Ave 4000." The house number is 10763, so the dispatcher should have said, "10763 Valleyheart Drive, cross street Riverton."
Continuity mistake: After John heads down to the victims of the cave-in, when they send down the drug box with the HT, the trauma case is still beside Roy, but when Johnny asks for the blankets the trauma case is gone. Then Johnny gives Roy the victims vitals, and when Johnny goes to the vent pipe to get the blankets they just sent down, suddenly the trauma case is down below with him, and it's open, but Johnny never retrieved the case before getting the blankets. Additionally, Roy tells Rampart that the victim has a "large discoloration on the chest", even though John never said anything about it to Roy, when he gave the victim's vitals over the HT.
Visible crew/equipment: When Johnny and Roy get back to the station and walk into the day room, right after Marco says, "Well, either he's sick, or he's the laziest dog ever lived," we can see the shadow of the boom mic moving back and forth across the top of the wall, on the right.
Continuity mistake: At the start of the episode, we see the squad and engine pull back into the station, and one of the guys - it would be either Marco or Chet, is standing on the engine's tailboard motioning to Mike, who is driving backwards, but in the next shot both Marco and Chet are seated in their jumpseats as Engine 51 comes to a stop.
Continuity mistake: At the structure fire, when Roy and Johnny rescue the man in room 22 by breaking the window, the door to room A is right beside them and we can see the axe mark on the door and the damage to the wall. When Johnny and Roy go back through the window to look for the missing Dr. Bennis, as Johnny uses the K-12, the door to room A now has many more axe marks and the damaged wall is far less damaged.
Continuity mistake: At the structure fire, before Roy and Johnny go back through the window to look for the missing doctor, Johnny's and Roy's SCBA cylinders have no stickers, but when Johnny's cutting the door, his tank now has two white stickers and Roy's tank has one on the side, then when they're back outside the stickers are gone.
Character mistake: When Squad 51 is dispatched to the fighting couple the first time timeout is 10:12, and the second call to that house timeout is 12:37. When Roy and John are there the first time, it's for no more than five minutes. Then when they're there the second time, Roy says "Please folks, we just went through this less than an hour ago," though it was over two hours when they left the fighting couple the first time.
Continuity mistake: When Roy and Johnny get back to the station, after the cave-in rescue, the dog is lying on the couch on the middle cushion, between Mike and Marco, but in Henry's closeup Mike is gone, and the right side of the couch is empty, then Mike's back, but he vanishes and reappears again.