This goof is from “The Smell of Music,” originally broadcast January 3rd, 1977. A wounded soldier named Saunders wants to take his own life and sneaks off to the O.R. from post-op where Potter finds him trying to breathe anesthesia in a suicide attempt. As he is inhaling the gas, you can see his bare feet as he sits and struggles with Potter over the mask.
As the scene ends, Potter and Saunders are walking out of the O.R. and you can see the patient now has on house slippers.
Thanks to EC for this goof.