I always imagined Loomis tortured himself over the death of Tramer. He was seconds away from emptying his gun into him on a street lined with trick-or-treaters when the Sheriff grabbed at his arm...forcing the drunk Tramer to head off into another direction...and into the path of a patrol car, and into the path of a van, and then, well.
Or maybe that was just my interpretation of the death of Tramer...maybe he didn't even see Loomis and his gun.
Image source.
Here's the scene. Just re-watched it. I'm afraid Loomis was totally responsible for Ben heading off into the path of a moving car.