Victim in critical condition
What are the odds
Wrong question.
If you want autonomous cars outside in the real world (as opposed to artificial lab and test scenarios), then they have to deal with real world situations. This situation has happened in reality. You don’t need to ask about odds anymore.
how can the car know which situation it’s currently in?
That is an engineering question. A good one. And again one of these that should have been solved before they let this car out into the real world.
This situation happened, yes. Do you think this is the only time that an autonomous car will ever find itself straddling a pedestrian and need to decide which way to move its tires to avoid running over their head? You can’t just grab one very specific case and tell the car to treat every situation as if it was identical to that, when most cases are probably going to be quite different.