I should say “The actor who played Radar...”
I didn’t say that he left to do another show. Just that he was pressured to take that part when it was given him.
An interesting fact about Radar coming into the operating room to announce Colonel Blake’s death was also a set up, to ensure Stevenson could never return to MASH. Up until the point of shooting, nobody was aware that Blake was going to die. The actor playing radar was supposedly given a cue card to read, just as he was going into the operating room to do something else.