I said this on another thread but it's worth repeating.
The winchmen training to be paramedics or paramedics training to be winchmen question is an old chestnut that is visited time and again on PPRuNe. If they are considering the latter, the simple question that Bristow need to ask themselves is are they prepared to conduct SAR operations with one member of the crew who has not been selected primarily for his aircrew qualities and secondarily for his ability to perform as SAR rearcrew?
What qualities are we talking about? His speed of thought, his ability to see the big picture, his understanding of the aircraft's safety parameters, his reaction time, his awareness of what the rest of the crew require of him, his vigilance, his athleticism, his resilience, his determination, his ability to think on his feet, his coordination, his ability to prioritise, his adaptability, his ability to offload the pilots and fulfil duties on their behalf (eg navigation), the speed of his comprehension, his performance under pressure, his ability to assimilate multiple inputs without reaching saturation point. The list is long and I've only just touched upon it.
Bristow may well have method of selecting ambulance paramedics who have those qualities and good luck to them if they do. However, these individuals are unlikely to have any/much flying time behind them. That will lead to a lengthy and frustrating training process if Bristow are to ensure that there is no reduction in the quality of SAR service provided in the UK when they take over. As I recall, the 'no reduction in quality' principle is fundamental to the civilianisation of UK Search and Rescue.