Revealing mistake: At the end of the 'crashed plane in a tree' rescue, Tom falls upside down in front of Roy and John, who are standing on branches way high up in the tree. Then just as the scene ends and the screen fades out, we can still see Gary Crosby (Tom) having fun jumping hard up and down on that "tree branch" that he's now also standing on, and Randy Mantooth starts cracking up.
Continuity mistake: When the babysitter runs into Rampart with the child who swallowed phenobarbital pills, Brackett picks the boy up and carries him into treatment 5 (window on door), but in the following shots from inside the room we can see they're actually in treatment 2 (windowless door and set up differently). Then after they place the pacemaker Dixie leaves the room, and in the shot from the hallway she's coming out of treatment 5.
Continuity mistake: While Brackett is treating the man who was in a fight, it cuts to Early walking down the hallway, and in the shot from the hallway he's entering treatment 4 which is beside the nurses' station, but in the next shot from inside the room we see he's actually in treatment 2, the one beside the receiving entrance.
Continuity mistake: After Sharon calls out Dr. Early's name in the hallway, because paging him didn't occur to her, when she finds Early they walk into treatment 2 in the shot from the hallway, but in the shot from inside the room they're all in treatment 5, not 2.
Continuity mistake: When Roy breaks the key in the squad's ignition, while he's holding the broken piece in the two wide shots there's something dangling from the key's hole (another key/keychain), but in the closeup it's just the broken bit in his hand.
Transition - S4-E15
Continuity mistake: When Gil's in the basket ride at the amusement park, while Captain Stanley swings the line that Johnny's hanging on, in the closeups the open cage door is facing Johnny, but in the long shot looking up the basket's open door is on the opposite side, and Johnny would not have been able to enter it as easily.
Transition - S4-E15
Continuity mistake: When Roy walks into the ER with the chemical burn patient they rescued from a kitchen filled with hydrogen sulfide, Dixie tells them treatment 1 which has a windowless door, but in the shot from inside the room the door has a window, and we can tell it's treatment 3 they're in.
Transition - S4-E15
Continuity mistake: After Brackett and Johnny try to convince Gil that he's not responsible for the MI patient's death, when Johnny walks out of the treatment room he says he's going to check on Roy, and as he opens the door we can tell that he's in the room across from the nurses' station. Then when he and Roy leave the treatment room where Early had examined Roy, we can see that it's the very same treatment room that Johnny had just been in with Brackett.
Continuity mistake: When Dixie tells Roy and John that Vic wants to see them the guys walk into treatment 2, but in the shot from inside the room we can see that they're actually in treatment 3, on the opposite side of the hall.
Continuity mistake: When Squad 51 is dispatched to the "possible assault victim," the address given is "743," but when John and Roy are at the scene the address on the house is 4015.
Continuity mistake: When Dixie walks over to the admitting desk and asks the nurse to stop what she's doing to set up treatment 4, the nurse places the black pen inside the metal folding clipboard and flips it closed, but in the next shot the pen is lying on top of the closed clipboard.
Continuity mistake: At the lion pit, when John loads the photographer onto the stokes he places the yellow blanket package under her head, and as Captain Stanley, Marco, and Roy lift the stokes out of the pit, we can see that the package is under her head the opposite way.
Continuity mistake: When Dixie gives John a tetanus shot because he fell from a skateboard onto cactus, we know they're all in treatment 1, because when Johnny and Roy are at the open door we can see the door and wall (with fire extinguisher) on the opposite side of the hall, but in the next shot from the hallway he and Roy are leaving treatment 4, which is opposite treatment 3.
Continuity mistake: While the boy who has cyanide poisoning is in the ER, Dixie looks through his clothing and finds carved peach pits, and when she directs Brackett's attention to all the carved pits, the items change when it cuts to the closeup. Additionally, that closeup starts out being farther, and we can see that Dixie is not beside the table before it zooms in.
Continuity mistake: When Station 51 is being dispatched to the fire and explosion at Martell Industries, the other companies called are Station 36 and Engine 14, but we see Engine 236 at the scene even though they were not called. This is before Captain Stanley asks dispatch for the second alarm.
Continuity mistake: During the fire at Martell Industries, when Roy and Johnny make a mad dash out of the building before the explosions, and midway Roy's helmet falls to the ground as he keeps running, but in the next shot when he and Johnny reach the engine and dive to the ground, the helmet is hanging around Roy's neck.
Continuity mistake: When Dick introduces Art Fromich to Roy and John, in the wide shots the Biophone is lying on its side atop the squad, but in each of Roy's closeups the Biophone is upright.
Revealing mistake: During Station 51's rescues on the foggy San Diego Freeway, when Chet is giving CPR to the little girl, it's just too obvious that he's not really giving CPR, unless her mouth is located on her cheek.
Revealing mistake: After Station 51 is dispatched to 'man trapped at the rock quarry', just before Squad 51 heads through the tunnel-like passageway, in the shot from the top of the squad we can see that the lightbar's chrome center and trim have been covered in black, presumably to prevent the reflection of the camera and cameraman, who's riding atop the squad.
I'll Fix It - S4-E2
Deliberate mistake: After Roy and Johnny rescue the man trapped under his house, when the ambulance reaches Rampart, in the shot from inside the ambulance when Roy follows the stretcher out, he stops at the receiving doors and waits for John, who just arrived in the squad, and in this semi-closeup, it's odd and very apparent that it's not actually Randolph Mantooth, it's his double meeting Roy at the door.
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.