In the novel

“Sunbae, do you just want to blame me, or are you trying to shift your own guilt onto me for not taking any action after seeing the photo? From my perspective, it seems like the latter.”

I get the gist of Park Juyeon is, he's a psychopath or turned to one because he doesn't have a single human emotion. He deflected the concern of Jiwook's friend Kim and making Kim partially responsible.