
Jitae didn't know Hajoon played a big part in his mother's death and believe his lies. But if he knew that his stepmom and grandpa were some of the bigwigs behind it already, it would make sense that he knows Hajoon is in it too.
I really hope it's Hajoon who died in the crash so he can keep his paws away from Jian. His existence is one of the reason why Jian can't move forward being sober.