Have you been reading the dialogue? His speech is rude 'are you going dressed like that?' Normal people remind you that you're wearing the wrong shoes. As his superior, he shouldn't speak like that to an employee and he does this constantly.
The uke is definitely stupid for assuming things without clarifying. However, it's been years so the seme should have straightened things out already, is he incapable of talking normally is that his quirk to make him look cute?? Its not, it makes him look like an assh*le.
I honestly think what you wrote can be the truth... Your points of a and b really match with what I was thinking... Besides its not like he told the uke to go off and die.... Sometimes we make mistakes by not thinking clearly about what we speak which may or may not eventually seem as something serious for that person and hurt them a lot and that's exactly what happened with the seme who's personality is the not friendly one..... and honestly in all my years of reading yaoi mangas I've read many semes who were assholes at first but eventually turn good or fluffy at the end that it doesn't surprise me anymore of how bad they can be
So from what I’ve read I don’t think it was the seme who spread the rumors.....
He seems like someone who keeps to themselves and doesn’t care about the people around him enough to do and stop anything. I feel like it would have been the boyfriend of the uke or the girlfriend of the seme but more likely the boyfriend. The seme’s comment “take it as a free life experience” feels more like “now u see that u can’t trust everyone, take it as an experience before u get out into the real world.” The seme probably found out that the boyfriend did it and (a) was reluctant to say because he didn’t want to hurt the uke or (b) didn’t bother to say cus he didn’t care enough about what the uke thought of him to even consider telling him. Either way, there is no evidence that the seme did it other than this throw away comment that the uke interpreted on his own. Heck he’s barely said anything since the series started idk how people r so quick to judge him as an awful person.
Also MVP dad for saying that