the front seats may have broken if there was a lot of random heavy goods unsecured in the back of the car. but I doubt it. but if you got hit from behind heavily even that wouldn't have happened.
cars are mean't to have crashs forwards, if you know what I mean, i.e you fly forward, airbag/seatbelt stops you and pulls you back into your seat.
since the accident happened the other way round where the occupant was thrown backwards into the seat, it would have experiance forces it wasn't nesseerily designed for.
theres also a weight issue, I don't mean to be rude in any way, but if you are big (more than say 17-18st) then that wouldn't help.