There are lots of ways a person, or a group of people, can act obnoxiously or make others feel stared out, pushed to the sidelines or kind of uncomfortable without bumping into what would be legally offensive. Pointing at others - strangers in the same room - and cracking jokes about them, burping and making gestures, talking so loud that the rest are forced to listen to the conversation three tables away, or regularly bringing in people who are being a bit difficult socially while they (the hangarounds) are not ordering more than a beer or two over the whole evening. Any bar owner dreads that kind of thing.
We don't know enough about what went on for the plain reason that journalists refrain from giving any specific details in this kind of story (as pointed out by myself earlier in this thread). If it's a sensational murder you may get a lot more detail, but in this kind of thing it's very rare for news media to offer much detail even though they may have picked up a good deal. They don't want to risk getting pulled into new lawsuits or bad publicity, or they want to give a certain spin to the story - the Huff is a fairly liberal news source, but not infallible.
Okay, I suspect the real reason Penner became disenchanted with the T-girl group could be that he considered they hijacked the place on friday nights. Took some of the best seats, acted up, cracked mean jokes at the expense of the other guests and really outstayed their welcome. I've seen that kind of thing happen on social occasions nd at clubs a couple times and it's almost impossible to counter if there isn't a backstage area where both sides agree to talk and find a solution, to make a deal out of sight of the others. If it's a couple acquaintances or guests whom the host doesn't really know personally, I mean privately, it's near impossible to solve the issue by saying "look, you shouldn't do this, do that, talk so loud" and so on - it will only trigger replies along the line "but I saw this other guest doing the same thing three weeks ago and they didn't get kicked out!"
Yeah, maybe the discomfort to the other guests had something to do with this group being trans. The bar man was honest enough, or non-shrewd enough, to imply some of this when he told the T-girls they would have to make their visits a bit more scarce (he may not have flatly banned them for good at first; I think that's a grey area in what we get to know). But the unease, or transphobia (again, a grey area: feeling uneasy or weary about somebody's attitude or the jokes they make in your presence doesn't mean one is transphobic) seems to have been on the side of some of his guests, not part of his own outlook. And it's likely that it was more centered on somebody's actions and attitudes - those of the T-girl group, of the people they brought along, or interactions between the transwomen and the other guests - than about their being TGs. If the idea is that he had a duty to keep running the bar and hold it open to them as a charity operation, even though what wnet on was seriously hurting his business, then I beg to differ.
Maybe the T-girls felt they had a right to push others to the sidelines because they had experienced being pushed aside and snubbed in the past. IMO that doesn't hold water, one is not entitled to make other people extras in your own show just because they are straight white men or whatever.