How exactly does one "prevent" lane sharing? Opening your door?
I've heard of a door being opened...But...of all the stupids, I just have a hard time, wrapping my head around someone so stupid they want to have their door ripped off (course maybe the door was wrecked before, and they are looking for it getting replaced anyway).
More likely a Mental defect driver just drifts over to close the space, because they saw (or heard) Ya coming and thought...No way is that bike passing me.
Ahh...Mental defect can think that (and it has come up for me, on 101, near SF Airport)
But...Your on a bike. It goes, It stops, It slices, It Dices.
Keep a cool head, don't let emotions or crap, work your controls.
Wait a micro second if you have to, or find a different path if you have to..
Mental defect can not stop your split, ...might delay your split for a micro second..but BFD...You're making better time than the other options give.