Ah, nature. Fresh air, mountains as far as the eyes can see, and a monkey with machete cutting people left and right.
Now this is truly survival of the fittest, both in brain and brawn also luck, the ones who fell and suffered from injury were having bad luck after all.
As for the chapter, can't really blame if some of them don't want to climb back up, the damn monkey was there. But then again, going down was clearly a trap.