I was wary of how they would finish all stories in a single episode but they did a decent job. cheers to that. But I would have loved if 2nd and 3rd sister's love stories were more fleshed out. Overall 8.5+ from me.
I am not convinced, I think it is Sun Jin and she is diverting the blame to him, we know that her dead ex went…
I think it would play like this : Hyeok Chan returned from Holiday, ML told him the truth about him talking to FML, H.Chan says why are you meddling I was going to break up with her or something and then ML hit him... And then The Blast was a accident and no one to blame, I don't know how that doctor is so sure it was because of that Container, wouldn't it be on news the reason of Explosion... That's my assumption for the Flashback.