actually i was having this suspicion that he might be the one behind this accidents, but well i hope it's not tho
but actually well I really don't think Minjae is like that, he just look so suspicious but maybe it's clear pure coincidence and that maybe it is the family feud cause of inheritance money and all.
I thought that at first too, but then Heexhan believed he was bringing him bad luck and stayed away because of it. Minjae is extremely perspective and could tell that’s what he was doing. I think for someone who loves Heechan as much as he does, he wouldn’t have continued this if it meant Heechan would stay away. I believe he was genuinely in danger and he didn’t insist on Heechan being close by because he worried about Heechan’s safety.
i think minjae's the one who planned all those incidents like he did say he'll find a way to keep heechan by his side.