SimonK, I'm not sure why your Puma QHI was trying to demo that, it certainly wasn't in the OCU syllabus!
Having said that, from personal experience of a similar nature, I can confirm that it certainly IS possible to get a Puma into FDVRS, even when you're not trying. I wasn't flying when the aircraft entered; but although I was in the LHS (but not acting as QHI), I did eventually "assist with diagnosis and recovery action" before we finally hit the ground with the VSI pegged hard on the bottom stop, in hostile territory too. We went from around 10,000 feet at max continuous power (job required a very high OGE hover) to ground rush very quickly indeed. It was twenty five years ago but I still recall it quite easily. Something I wouldn't wish to repeat in a hurry.