I'm glad you are okay. I think your analysis is just right, except I think "fault" is too strong in #2. Had you been injured, it would have been avoidable, but that is not quite the same as saying that it would have been your fault. I admire you for looking back and asking what you could have done differently though.

About freak accidents:
Just yesterday I was riding to work when a large dump truck with an unsecured load passed me. When it was maybe 30 yards ahead of me, the wind caught the underside of a sizable piece of plywood, which came flying out of the truck right at me. I slammed on my brakes, and the plywood landed about 10 yards ahead of me on the road. I can't even imagine what it would have done to me if it had hit me. I also can't figure out what I could have done differently. I never ride close behind big trucks, but I can't stop them from passing me. The driver never even stopped. I don't think he knew that he almost killed someone.