Yeah it is surprising that no airbags went off, but it looks more like they clipped something with the rear and then ended up on their roof. The front airbags would only go off if they decelerated quickly in that direction otherwise there's no point, would have thought the curtain/seat bags would have fired though.
I was going to say too, that looks absolutely screwed. There's no way anyone would buy that if it was repaired if they looked at these pictures. It wants stripping on any good parts and the shell scrapping. Even one of the rear lights is broken. Ever panel is damaged, even the rear bumper is scratched. Looks like someone went off a bank into a tree top first!