I suppose this sort of thing is bound to happen now and again. As a bar owner, you can set policy and you can discipline workers who disobey, but you can't ensure 100% compliance all the time. I hope the security guard gets fired, and I imagine the bar will find itself in some legal trouble.
I don't like the fact that the article found the need to reveal the victim's deadname and surgical history. That's a violation of privacy that compounds her victimization. It also smacks of gender policing - implying that her surgical history and the fact that she's a "beauty queen" has bearing on her being entitled to use the correct restroom.