
You and the commenter below are spot on! This was my second possibility. That maybe Guwon really DID kill the father, but his reason for doing so was established off-screen. Notice MC’s father was gone for a long time before he came back to him. We ASSUME it’s because he was struggling to find water for our MC, but we don’t exactly know WHAT he was up to during that time frame. Maybe he was being an absolute menace in the streets. Maybe he did something that got Guwon’s attention in a bad way. (Like stealing from him, as you said) Or maybe he had actually planned to leave MC to die, but Guwon found out about it, and forced him to lead him back to his son so he could assess the situation. Wouldn’t be the first time in a webtoon we find out that the parent was actually a scumbag all along. We’ll see….
I think what we might be dealing with here is an unreliable narrator/ an MC with an incorrect memory and I’ll tell you why:
Guwon is a murderer, BUT sneaking up behind a random guy and killing him doesn’t really fit his character. Everyone’s he’s killed so far, he’s always had a clear reason for doing so- even if that reason was fucked up. The doctor was just killed out of self defense, but everyone else was because they either broke a rule or because he didn’t think they were useful. However, he has always asked these people if they were useful before killing them. Remember the doctors family? He asked what their skills were first. Even with the man who broke the rules in the camp- he only killed him AFTER a majority vote and 99% agreement from the other villagers. He’s a killer, but there’s a method to who he kills. Therefore, just running up to a house and striking down the first guy he sees with no question really doesn’t fit him at all. He would have asked the father if he had any skills first. Not saying this is concrete proof, the evidence we’ve seen so far just really isn’t adding up to a solid case. Any lawyer would throw this out of court for being circumstantial at best.