Condolences to all involved. Sad as he was an exciting actor and passionate motoring fan.
Unfortunately the car is one that is very tricky at the limit or not very close. Start watching at around 6 minutes for Stigs' experience as Jeremy describes his feelings on the car. Not at all very forgiving even at lower speeds/dynamic loads.
BBC: Porsche Carrera GT Car Review- Top Gear - YouTube
Looking at the crash photos - the front wheels appear to be cranked into a slide to the right and the rears came around as the chassis was fractured severely if not broken in half. I would suspect the impact immobilized both of them and unable to escape the fire.
Many similar accidents at the Nurburgring in exotics that are tricky near the limit/unforgiving.