Ogsplash,
I did a Risk Analysis on this subject a couple of years ago for one of the EMS operators in Sydney. I will try to find it if you would like me to send you a copy.
The interesting thing is that pilots always say they need the cutter, yet none of my research showed any cases where the aircraft was put in a situation that could not be solved by manual cutting. (I had some interesting replies to a similar question to yours that I posed on this forum while doing my research. None of them stated a valid case for ballistic cutters; the best was from a pilot who said he had "almost had to use the cutters" during a flight)
The greatest risk is to the crew on the cable. In a professional EMS operation, the crew train as a team and winching is not an emergency procedure, but an access tool, used regularly and safely. With everyone in the chain maintaining situational awareness at all times, risk is very low of a winch related incident. Risk of a catastrophic aircraft malfunction during the short winch time is negligible.
Greatest proven risk is inadvertent cable cutter firing (I have personal experience of two) or activation by crew, or failure of the cable cutter to fire or sever the cable when needed. The former poses lethal risk to the winchees, the latter equal risk to all parties while the manual option is used.
I will check my files tonight and get back to you on private message.
