You are not alone. When they were driving where the accident happened I really thought it would be revealed Juyeon was the other driver lol. (not even that he wanted to hit them, it just happened.)
Which really shows WHY this story works: it wants you to THINK the worst of Juyeon, because every bit of the premise is every other abusive/kidnapping BL story. If you read a couple of those, you will be suspicious and wait for the big reveal that he was too in love and snapped and took the accident as opportunity to monopolize the man he loves.
But nope, every turn Juyeon is just a trumatized boy too in love and that really doesn't know what to do with his feelings and the whole situation.
Playing on the reader expectations to deliver a more poignant story was a smart move.
I've read those kinds of stories that made me like this, everything seems suspicious that almost everything that has the same scenarios are either someone killed someone and that someone was the closest to the lead like I'm not a mind reader nor a investigator why do I have to make myself overthink every damn thing!
I'm so scared at my own overthinking power, I thought that Juyeon might be the reason of the accident or he killed his own sister, but the mere fact that he stayed & waited up until he's better showed his love and dedication. This is so good!!