I believe Tesla's "Enhanced Autopilot" has additional cameras pointing backwards for this reason. They claim they were added to address the issue of cars approaching more quickly than the ultrasonic sensors are useful for, but I wonder if they would have found this biker too.

People will do it even if it's illegal, and it would be better for everyone involved if autonomous cars can deal with it safely.

This is why self driving cars are so much harder than one might think. Just getting the basics of self driving down is challenging. Now throw in all the possible edge cases, some of which shouldn't ever happen, and you've got a wildly interesting and challenging problem. It would be a blast to work on that team.