Loved this story, I also saw the short movie in the 80’s. Ray Bradbury had a science fiction show called Ray Bradbury Theatre. It was a bit scary and suspenseful.  The ending was unexpected. Time travel stories are always my favorite. They all follow the same theory that when people go back in time they shouldn’t disturb anything because it may have grave effects on future events. Good storyline even though the main character got what was coming to him.