If I remember correctly, it's been awhile. He hung up the phone that the alpha had been dialing the omega for sex. Instead of connecting him thru. Saying that "it's nothing" like it was a butt dial.
I could honestly be completely wrong bc its so hard to tell but maybe that's where he lost his reasoning.
But I definitely thinks he shoudl take accountability for his actions drunk or not
He did, he's apologizing but haewon (idk if it's the name I forgot) cut him off and take the blame for himself
Yoon did rape the alpha, but I don't think he wanted to? In chapter 3 I'm pretty sure it meant that Yoon gets affected by the pheromones, and when the alpha attacked him due to his rut, Yoon was crying and fighting back, but couldn't cause he was drunk. Also when he woke up he was in shock and didn't remember anything, he wasn't in the right mind. And the "I won't touch hyung, never" line in chapter 5. But idk he's still in the wrong imo