Revealing mistake: After the MI patient from the construction site is brought to treatment 1, when Early uses the laryngoscope for an endotracheal intubation, we can see that he merely places the laryngoscope at the side of the man's face, especially since we can still see the entire distal end beside the man's neck.
Deliberate mistake: After Johnny's and Captain Stone's efforts, when the construction site's cardiac arrest is wheeled into Rampart, the problem is twofold; First, we hear Roy's voice saying, "Full arrest, number four," even though Roy is not actually on this run (that line is from S4xE21 "Back-Up", when they wheel the cardiac arrest into treatment 1, after defibbing him atop Engine 51). And second, the attendant pulling the stretcher changes, and the EKG monitor lying on the patient is the old blue Datascope 850 from earlier seasons (this shot is from S4xE7 "Daisy's Pick", the hypothermic victim - note his wrapped foot!), whereas at the construction site and when he's wheeled into the treatment room, the EKG monitor is the newer white Datascope M/D2.
Other mistake: When the cardiac arrest is first brought into the ER we hear "Let's get him intubated," but the weird subtitles read, "Let's get him elevated." Subtitles from Universal Studios 2010 DVD.
Other mistake: At the construction site, after Johnny administers the epinephrine to the cardiac arrest, 39's paramedic resumes CPR, and when they're lifting the patient onto the stretcher Johnny says, "Stop CPR," but the subtitles read, "Start CPR," which makes no sense since they've been doing CPR all along. Subtitles from Universal Studios 2010 DVD.
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.
Continuity mistake: When Chet is brought into the ER after being thrown in the explosion, Johnny is empty handed, but when he leaves treatment 1 with Dix, the HT is suddenly inexplicably in his hands.
Continuity mistake: While Early, Morton, and Dixie are examining the young boy who fell, Early's wearing a gold ring (wedding band in real life) on his left hand's ring finger, but when Dixie finds the tick she asks Early to have a look, and in the closeup of the boy's head, Early's gold ring has vanished.
Continuity mistake: When Engine 8 is dispatched to "man unconscious at construction site," we see Engine 8 going past Curson Ave, then the next shot Engine 8 is driving up from the other direction of Curson Ave and passes it going the other way. Neither are flipped shots. Other than seeing the sign for Curson Ave, other giveaways are the same signs or parked vehicles.
Revealing mistake: When Engine 8 rolls up on scene at the warehouse fire, as it passes the camera in the overhead shot we can see the real company number 60 printed on the surface between the jumpseats.
Character mistake: At the construction site, while the paramedics are defibbing the cardiac arrest Stoney's on the line with Rampart, and Brackett orders, "Administer 5ccs 1 to 10,000 epinephrine IV," to which Stoney responds, "Administer 5ccs epinephrine, 10-4, LA," even though he's speaking to Rampart not to LA dispatch.
Continuity mistake: During this episode Brackett is wearing a tie with white, light blue, and dark blue broad stripes, which should be tied in an identical manner in consecutive shots, but it's not. One example is when Brackett examines the tree surgeon, but when he waits in the hall with Morton and Dixie while Malcolm takes x-rays, Brackett's tie is tied differently, and when he walks back into the room the tie reverts back.
Continuity mistake: When Roy's injured during the warehouse fire and is carried out, in the closeup he and Johnny are not wearing their turnouts, but in the next wide shot Johnny's suddenly wearing his turnout again as he contacts Rampart via Biophone.
Continuity mistake: After Roy finds Willy, when he calls Captain Stanley to help get Willy out, Roy's on Willy's left and Captain Stanley's on his right as they rush out, but in the next shot they've switched, Captain Stanley is now on Willy's left and Roy's on his right, just before the explosion.
Visible crew/equipment: At the construction site with the cardiac arrest, the outline of the lavalier mic transmitter is visible on the back, left side of Johnny's shirt, particularly when lifting the man onto the ambulance stretcher.
Continuity mistake: It's Squad 39 at the construction site with the cardiac victim, but en route to Rampart we see Squad 51 following the ambulance.
Continuity mistake: During the warehouse fire, Johnny removes his turnout when Captain Stanley calls for the ambulance, then when the ambulance arrives John's wearing the turnout and one burn victim has the sheet over him, but then the turnout and sheet vanish, and as the ambulance attendants bring the stretcher, Johnny places the sheet on the victim, and in the overhead shot as Cap is told about Willy, Johnny's wearing his turnout again. The Biophone also keeps jumping from being beside Squad 51 to being between the victims.
Deliberate mistake: After the fireworks begin exploding at the warehouse fire, when Captain Stanley and Roy are helping Willy out, they are knocked to the ground by an explosion, and in two of the following exterior shots the large sign that reads "Kiddytime Toy Co" is visible. This shot is from season 4, episode "The Screenwriter", when the guys respond to the fire at the toy factory that also made fireworks.
Continuity mistake: When Johnny is doing overtime with Engine 8, dispatch sends the two guys of Squad 8 on an unknown type rescue and they leave Station 8, but when Johnny and Captain Stone walk back into the kitchen, Squad 8 is still parked in the apparatus bay.
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.