Visible crew/equipment: When Johnny and Roy are on the soap opera set treating the 'doctor', the outlines of the lav mic transmitters are visible on the front, left sides of Johnny's and Roy's shirts, above their belts, and the outline of Jody's mic transmitter is visible on the back of her brown sweater.
Revealing mistake: At the movie studio, when the actor who plays Dr. Ned is loaded onto the ambulance stretcher, their set's 'fake' window area is the same as Rampart's 'real' hallway later in the episode. We can see this when Brackett, Early and Dix walk down the hallway to kick Dr. Ned's film crew out of his room. Pretty funny to see the same chairs, wall, window with painted exterior backdrop and color stripes on the floor. This area of Rampart can also be seen in the previous episode 'Family Ties', when the clock radio shorts out causing a fire in the patient's room.
Visible crew/equipment: When Roy and Johnny are stuck in the elevator with the cardiac patient, the outline of the lav mic transmitter is visible on the front, left side of Roy's shirt, above his belt.
Other mistake: When Johnny, Roy, and the cardiac patient are stuck in the stalled elevator with smoke in the shaft, Captain Stanley notifies dispatch that he wants a full first-alarm assignment, and we then see Engine 8 pulling out of their bay and heading to their run. The problem here is that this shot of Engine 8 is from the episode "Equipment" in season 5, when Johnny was doing overtime with Station 8, and we can actually see Johnny sitting on Engine 8 as it drives by.
Visible crew/equipment: When Roy walks into the ER with the actor who plays Dr. Ned, the nurse rushes over to Roy, and when she asks him about the actor, we can see the bulge of the lavalier mic transmitter at the back of her uniform.
Continuity mistake: When all the guys enter the apartment with the doctor lying on the couch, John's carrying the Biophone with his right hand and starts to place it down, but then it cuts to another angle and John's holding the Biophone in his left hand as he places it down.
Visible crew/equipment: After we see Marco and Captain Stanley heading up to the roof, it cuts to a shot in the elevator when Roy says "The firemen are working as hard and as fast as they can, to get us down from here," and the crew's moving shadow can be seen on the left, where the camera is located at the elevator doorway.
Continuity mistake: After Early tells Dr. Ned that he thinks he has mononucleosis, when Early leaves the room, the nurse that's in the room with Dixie walks away from the patient to the other side of the room, but in Dr. Ned's closeups that nurse is still standing behind him while he talks to Dixie.
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.