The bit about leaving his Swiss Army knife but having to use a Leatherman didn’t ring quite true, I’ve got both and the saw knife on my Leatherman nearly takes my arm off every time I open it. It would be easily capable of sawing through flesh, assuming it was still intact, maybe I missed the part where he broke it.
If you watch the film properly though, he says it’s a cheap crappy Chinese copy of a Leatherman and a very well used one at that. And besides, he’s been chipping away at a lump of sandstone for 2 days with it!
My Gerber multitool (basically the same) is phenomenally sharp, fantastic bit of kit.