Shouldn't FSD understand how to drive properly when emergency vehicles are approaching from behind? Otherwise an ambulance could get stuck behind a Tesla blocking the road. Or was this just adaptive cruise control?
This doesn't say what mode the driver was using, FSD could arguably want to understand this, but if he was just using "Autopilot" (aka keeps your lane + adaptive cruise control) with a steering wheel weight to disable the "are you there?" checks, I wouldn't expect that to need or understand anything about emergency vehicles.
FSD isn't Autopilot. Autopilot does detect emergency lights (in the US at least) but it only slows down.
I've wondered why the car doesn't have detection for approaching cars behind to get out of the way but people say the rear camera angles are not good enough - I think that's a terrible excuse.