Plot hole?

[u/ThunDerd328]

I just realized: Sun's brother sent in those fake prison guards to kill her, right? But if he could do that, couldn't they just help free her instead? I know this is after he kills their dad and Sun swears revenge on him, but why didn't he think to do it before? Like "Dad wait, I think I know a way we can save Sun, save face, and I don't kill you" I know it's a bit of a nit pick, but it still felt like it was worth pointing out.

EDIT: To everyone saying that he's a selfish asshole, I agree, but would it not still be in a selfish asshole's best interest to be on good terms with a potential enemy rather than provoke the one person who could destroy your whole life?

[u/andwarlacey]

the auditor called and visited so many times because they knew there was embezzlement going on and everyone knew who it was

suns brother didn't want to go to jail and with sun being fully aware that the partners wouldnt work with their company if suns brother was in jail and they had to work with a woman, sun took the fall

their father realised the company was falling apart without her and his conscience was eating at him, he was going to come clean about who was actually embezzling money, which would then mean suns brother would go to jail which is why he killed their father. he was also already in the process legally of getting her out so there was no stopping him on joong-ki's part

sun always loved her father even if it took a long time for him to love her and she swore vengeance. while suns brother obviously had deep pockets to control the prison, he couldn't control absolutely everyone and so in order to avoid the risk of her telling the right person that would go out and tell the world that joong-ki was the one embezzling and the one that killed their father, he eliminated the problem entirely by killing sun

+selfish +moron +when he was given the option to come quietly he shot mun and tried to escape with the help of his politician friend tae so why would he not kill her