Visible crew/equipment: When Roy and Johnny are with the teenage girl who OD'd, Roy walks over to the bystanders, and when he speaks to the mother and daughter, the perpendicular actors' marks are visible on the ground where they stand.
Visible crew/equipment: When the truck driver who felt like his head exploded is in the treatment room with Early, Brackett and Dix, as the camera passes behind Brackett it casts a moving shadow along the two walls.
Visible crew/equipment: When Roy walks into the ER with the man who attempted suicide three ways, due to the low angle of the camera we can see part of the unfinished ceiling of the ER set, near the nurses' station.







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.