I think it would be almost impossible to saw through bone (especially your own) with a SAK, even the big one with the rip saw. But it did say "below the elbow" so - if I had to guess - I'd suggest maybe the bone was already broken clean through and all he had to do was cut through the soft tissues.

I also suspect he may have applied the tourniquet *before* starting the amputation, not afterwards as the article stated. Otherwise, he would probably have died from loss of blood while trying to perform the amputation.

He seems to have made some poor decisions prior to the accident - why did his employer and co-workers wait four days to report him missing, for example? If you're hiking alone, this is an excellent example of why you should leave a "flight plan" with someone who's reliable enough to realise "empty desk = maybe we should call him and see if he's okay". But tbh, if one of my co-workers didn't show up on Monday, I might equally well assume he/she had phoned in sick or decided to take a couple of days off.