This seems reasonable AS LONG AS: Motorcyclists ALONE accept ALL FINANCIAL LIABILITY for any accidents resulting from a collision that occurs because a lane splitting motocyclist flies out of nowhere into a motorist who has the misfortune of trying to change lanes when the lane-splitter shoots through.
Most splitting takes place between two cars adjacent to each other.
Your thesis fails. Lane splitters won't often be hit by cars changing lanes (for they can't change lanes, when there is another car next to them), or else it wouldn't be called splitting.(!)
I've only split lanes myself, when traffic came to a crawl, then I would only pass carefully at about 5-10 mph more than the stalled or slow traffic.
Let the rider decide. Then, if the cop says, "hey buddy, too fast, unsafe" the rider can sign, then pay the ticket. If he ain't dead.