Either the author forgot or my theory is that maybe it was his father who was going to kill him (as a zombie perhaps) and Guwon actually saved him? I don't see why else he'd kill the dad, and then it could be that Jinwoo's memory just mixed it up because he doesn't want to believe that his dad would do that (or that he turned into a zombie). We don't know much about his dad or what happened to him so anything is possible. But I hope the change is intentional and leads to a plot twist later
Go between Episode 0 and 24 to compare the scenes.
Episode 0 Jinwoo is hurt and cannot comprehend what's happening around him because he's close to dying/passing out and has a head injury.
He hears a lot of things happening (Raiders robbing and attacking others) and misconstrued the events due to his injury. That's why you can't see the raider clearly in Ch 0 and his speech bubble is black. The thing he is holding is purposefully placed off screen. Ch 0 you think it's a weapon, but in truth it's a water bottle. The last dark speech bubble fades into white, as if the truth is barely peeking out.
Ch 24 reveals the TRUTH. There's no dark shadows hiding anything. The scene is completely clear.
A raider DOES appear, but is chased away by his Dad. To Jinwoo the two of them merge as the same person in Ch 0. His Dad returns and the scene from Ch 0 plays out with his Dad's real dialogue, some of which is similar ("look what I found" vs "there you are" in reference to finding Jinwoo). His Dad mentions having been chased by some guys (likely the Hounds), but says he got away and as he holds out the bottle, Guwon smashes his head in, killing his dad. The bottle falls and lands on the floor. In Ch 1 we can see it on the ground next to the Dad's body. But do we see a weapon on the ground anywhere? No.
Jinwoo passes out for a bit and when they are on truck he wakes up. Guwon had taken the water and is now giving Jinwoo water to drink. At the time we don't question where the water bottle had come from, but now with the truth revealed we know Guwon took it from the Dad.
Guwon later lets Jinwoo come back to where Jinwoo's Dad's body is left. It's a surprise! Since Jinwoo said he wanted to get his memories back on his own Guwon pretended he didn't kill Jinwoo's Dad when Jinwoo asked him earlier, because then the surprise would be ruined! He didn't lie he says! It was just a secret so his surprise wouldn't get ruined. You know? Just like when you lie about a surprise birthday party so that it stays a surprise! How nice of Guwon! Lol When Jinwoo confronts him Guwon finally does admit he killed his Dad, but obviously to Guwon this is not a big deal so he doesn't get why it's upsetting. He just thinks he did a good job on his surprise!
So Jinwoo in S1 is unreliable because of his memory issues. The reveal at the end of S1 has his real memories come back and shows the truth: Guwon was not his saviour like he thought, he had killed his Dad. The way his heart pounded near Guwon may have actually been a natural fear response and not love like he thought. His body remembered, even when he didn't.
Im acc confused if guwon killed his dad or not. Cuz so far we've seen that jinwoo is lowkey an unreliable narrator Because now in the last episode we see guwon kill his dad but in episode 0 it was a random person who entered the house and was about to kill jinwoo and then guwon killed the stranger first. So did the author forget is there smtg wrong with his memories?