Uh, dude, where did you come to that conclusion? Are you assuming that these guys were not paying attention, or do you have a link to some info? Seems kind of rude to me to say this about some young men who by all accounts were challenging themselves in unfamiliar territory.
A couple years ago a bow hunter was killed in southern alberta, I couldn't find a news link (sorry) but from what I remember the post showed that he had been killed almost immediately from one or two blows. He was quite probably ambushed, and was an experienced outdoorsman and hunter. Sometimes these things happen. Maybe the bear didn't hear them over the water. Maybe, Maybe, Maybe. We can arm-chair quarter-back this one to death, but it does those young men great disrespect to not acknowledge that they over came a pretty major ordeal. It's not like they sat in a corner and cried until help arrived, they made a good plan and carried it out, probably saving the lives of the two that were most hurt.
I have no doubt those young men had knives, but I've watched more than a few people get rattled at miss a shot from 6 feet in a shooting range, never mind with real fear and adrenaline. I suspect that my skills with a firearm are not sufficient in those circumstances, and I consider myself to be quite competent.
sorry my thoughts are a bit scattered this evening.