This nearly happend to me but I would not let them take the vehicle as I was told once it is in their control it is a lot harder to fight the case.
I also had a customer with a scenic, somebody brushed up against the two o/s doors, they still opened and shut ok but the assessor wrote it off as beyond economical repair. The customer thought sod it, i'll keep it as it is and not bother claiming as he did not want to spend the additional money on a new car and could not get a replacement with the money they offered and it was in quite good order. But the insurance company told them it was now theirs and as having been assessed as a write of it was now unroadworthy and could not be used.

I had suspicions that they could get more for the salvage than what they paid him so it was benificial to them to write it off and pay him less than they received.

Graham

PS - Martin, i've sent an email