he probably assumed that as you were already so far out that you were going to come out further so he couldn't go round you, and this was the only way he could stop himself hitting you.
he has made an assumption on what you MAY do, but you didn't do it.
i understand why he chose to drop the bike rather than risk going over your car.
do you have any witnesses? or were there any cameras about?
i don't see how you can be to blame for wht someone thought you may do, though it does depend on how far out on the road you were, as to whether his assumption was justified
did you take pictures?