
Teach obviously killed his own dad. I think his dad attacked him first though since the image of the guy holding the bat is his dad.
But after he witnessed Guwon murdering someone, his brain is filling those memories with him instead so that Teach doesn't need to face the trauma of what happened.
But, Guwon smiled and brushed off Teach's question like he just did with the kids which is heightening his paranoia. Either way, it looks like we'll finally be getting some scenes away from the town. I suspect that Guwon won't want to take Jinwoo, but will give in eventually and something bad will happen while they're out.
Could also be how we get introduced to all the "hounds" if he goes with them on one of their regular trips.