I wonder how widely reported that incident was at the time.
There was a movie called "Wild In The Streets" with a Morrison-like messianic singer. He runs away from home as a late-teen after trashing the house and blowing up the family car. His mom (played by Shelly Winters) sees him on tv one night and makes an effort to see him backstage after a concert.
Great movie to watch while high, so I recall.