from witness reports inside the pub, it seems to have been a 2 stage event, with the heli ending up the roof with more control than just gravity, followed shortly after by the wooden roof collapsing under the weight. So providing these witness reports are factual, some level of auto-rotation control was still possible. Pure gravity would have smashed right through the ceiling.
If thats the case, wouldn't the crew survive ?
Sounds like a high impact/heavy landing causing structural damage to the roof which subsequently failed.
Personally I would expect to survive a 7-8ft drop whilst strapped in / plus roof below you.