What you are describing is not unusual. Triggers come from strange places sometimes, and we don't always understand where they come from.

The weirdest one I ever had was from a Peter Gabriel concert video my son loaned me. I think it was the one in Athens in '87, I'm not sure since I turned it off, put it back in it's case and gave it back to him.

In it, Peter was singing the song, "No Self Control" and the lighting booms were coming down as if they were attacking him and he was rolling around back and forth trying to get away, but he was surrounded by them. That so freaked me out I ran out of the room crying. Luckily, I was alone, so I wasn't committed.