I enjoyed the film greatly but completely missed the explanation of what did happen to the guys brother. I just couldn't hear it properly and the scene was so dark I couldn't make out what he did with the knife.
Can someone please explain what he said and what happened between them?
As I understood it, the survivalist and his brother (Augustus) were raiding one of the other camps. Augustus found a woman and raped her (or it may have been consensual, but the result was they got noticed and chased). Augustus fell and couldn't walk so in order to hold up the pursuit, the survivalist cut his brother's achilles tendon to cripple him. So he basically sacrificed him to save his own skin.
I thought it was the other way round, the survivalist fell and when his bro came back to help he cut his leg so he couldn't run and the survivalist could escape. Hence he is the survivalist as he does whatever is needed to survive.
I think his guilt at that is seen a couple of times in the film, and at the end, he sees his brother and this guilt makes him sacrifice himself to save the girl and his child.
I just rewatched this scene and it's definitely the survivalist who fell and he yells to his brother "help me". His brother comes over and the survivalist slits his ankle and gets away. That's even darker than I thought! I originally had it the other way around lol. They should've gave the brother a different haircut they looked exactly alike especially in the dark! It would've helped clarify the scene more.