Visible crew/equipment: At Rampart, when Gage and DeSoto walk into the staff lounge, where Dixie and Dr. Brackett are seated at the table, there is an actor's T-mark on the floor behind Dixie, where DeSoto stands.
Other mistake: After Roy has found the location of the boy trapped in the collapsed building, Captain Hammer gets on the handy-talkie and says "Engine 51, Stoker," but oddly enough the subtitles read, "Agent 51, Stoker." Subtitles from Universal Studios 2010 DVD.
Visible crew/equipment: On site at the construction accident with the back injury victim, when Roy climbs over the tower's railing we can see the yellow canvas strap attached through the leather loop of his lifebelt, but when he descends to the injured victim, the yellow canvas strap is now also attached to a carabiner protruding from under his turnout coat, by his pants, which presumably is attached to additional hidden support.
Continuity mistake: After Squad 51 is dispatched to "possible heart case" when Roy and Johnny walk into the house, we can see in the hallway and there's a bureau against the wall, but when they leave that bureau is gone and now there's a painting on the wall which we should have seen in the earlier shot, but it wasn't there.
Continuity mistake: At the start, when Roy finds Johnny in the squad reading '1000 Practical Jokes', Johnny's window is rolled down, and Roy places his arms over the passenger side door then leans in to talk to Johnny, but in all of Johnny's closeups Roy's arms are gone.
Visible crew/equipment: On site at the construction accident, when the man with the back injury is lying in the stokes and being lowered with the ladder, a crew member/cameraman is visible on the landing at the lower right side of the screen.
Cook's Tour - S1-E4
Visible crew/equipment: At the construction site, when Johnny and Roy climb the tower mast, they stop on the blue platform with the crane operator's cab before continuing up to the main jib. When Roy, Johnny, and the man they rescue walk back across the jib the man slips, and there are a few shots showing the underside of the blue platform, and we can see people moving around on that platform overhead. There should only be four people on the tower crane: Roy, Johnny, the man they rescue, and the officer holding the bullhorn, who's standing at the other end of the jib, by the mast. Nobody is supposed to be on that platform.
Cook's Tour - S1-E4
Visible crew/equipment: At the construction site, when Roy and Johnny walk across the tower crane's main jib, there's a shot of the entire top of the crane, and we can see the cameraman at the tower peak, who is shooting the footage of the stunt guys from the overhead angle. He wasn't in the previous long shot of the crane. This does not refer to the officer who is standing on the main jib.
Cook's Tour - S1-E4
Continuity mistake: At the station, when Gage and DeSoto are eating the meal DeSoto prepared, the sealed milk container is suddenly open and then sealed again, between shots. It changes position as well.
Cook's Tour - S1-E4
Other mistake: When Johnny and Roy are with the man who was electrocuted in his house, after they start the IV, Johnny says that he's going to get blankets, so he walks out the door then turns left and walks off. It's funny because the squad is parked on the street, which is to the right of the door, and the only thing to the left is the garage. Then Johnny comes back, again from the left of the doorway, with a package of the yellow blanket from the squad.
Cook's Tour - S1-E4
Revealing mistake: After Squad 51 is dispatched to the 'electrocution in a house', while Johnny goes to the garage to turn off the power, Roy waits at the doorway to go inside to the victim. In this interior shot facing the doorway, we see what is supposed to be the brick chimney at the side of the house next door, and the top of that set is visible. Plus the fact that this chimney is not nearly as deep as the one they passed by in the exterior shot.
Cook's Tour - S1-E4
Visible crew/equipment: When Engine 68 pulls into the site with the suicide who has changed his mind, there is an actor's T-mark on the ground behind DeSoto, as he puts on his jacket.
Cook's Tour - S1-E4
Visible crew/equipment: When Engine 51 returns, after Gage and DeSoto have finished their beef bourguignon, as they walk into the kitchen the actors' black marks are visible on the floor, where they are about to stand.
Cook's Tour - S1-E4
Visible crew/equipment: When Jay walks into the ER treatment room, where his unconscious brother has possible brain damage, two white marks are visible on the floor, behind Dixie, and another couple of marks will become visible as this scene continues.
Cook's Tour - S1-E4
Visible crew/equipment: At Rampart, after the baby's birth, when Gage and DeSoto walk over to Dixie, the first actor's T-mark is visible on the floor just before Gage stands there, and a second actor's mark is visible under the stool, where DeSoto will be seated in a moment.
Cook's Tour - S1-E4
Continuity mistake: When Squad 51 arrive at the house with the woman in labor, first there is a wideshot of the home and front yard. In the next close-up, the actual style of the house changes - note the roof and its three dormers, and bushes appear/disappear.
Cook's Tour - S1-E4
Visible crew/equipment: After Roy and John pull up to the house with the woman in labor, when the deputy pulls up behind Squad 51, the reflection of production equipment alongside the lamppost is visible on the car's surface. In the previous long shot of the house, we see there is only a large area of grass in front of the house.
Cook's Tour - S1-E4
Other mistake: When Johnny and Roy visit the woman they assisted in delivery, they go through the ER's double doors opposite receiving, as if heading upstairs to her room, and soon she even comments that the baby was brought up to her from the ER. Then, when the guys leave her room, Roy pushes open the door on the right, and we can see the ER's treatment 5 and the silver cabinets right up the hallway, so we know that Roy and John were actually in the room just off to the side of the nurses' station in the ER.
Cook's Tour - S1-E4
Continuity mistake: When Roy and Johnny are dispatched to the home of the woman who's in labor, the deputy shatters the door's pane of glass, but there is absolutely no glass on the carpet once they enter the house.
Cook's Tour - S1-E4
Continuity mistake: At Rampart, after delivering the baby, when Gage flirts with the two nurses the amount of soda pop in the nurse's bottle increases considerably between shots.
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.