Above and Beyond... Nearly - S5-E20
Revealing mistake: Dixie and Brackett rush onto the elevator with a crash cart to go up to the third floor, for a possible MI in the dental clinic. The camera's POV is from the elevator, and in one continuous shot, without cutting away, we see the ER hallway through the open doors, then the doors close and in a few moments the doors open on the third floor. Even though the set has changed a bit, we can tell it's still the ER hallway by things such as the same scuff marks on the floor, and we can also catch a glimpse of the paramedic status board on the wall, where the base station room is located.
Above and Beyond... Nearly - S5-E20
Revealing mistake: When Roy and Johnny are on the cliff loading the unconscious victim onto the stokes, as they try to lift each of the victim's legs, we can see the unconscious man also lifting his own leg to assist the actors.
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.