Maybe. but its equally crazy to step to someone you dont know on a bus and start pressing them about shyt they dont know about.
I've been in similar situation with the OP riding DART (except it was actually a man stepping to me) and I simply pushed him out the down the steps (the middle section has a lower elevation than the others).
Had no idea who he was or what he wanted (had my headphones on), but he had no business being close enough to me that I could smell dudes breath
If you get in someone's face, you deserve what's coming to you
But
there's alot of crazy/homeless people riding public trans so you gotta be careful that you dont beat up a mentally ill person..