Left unsaid is that this may very well have been part of domestic violence training. I have no idea what OP means by "heated" but if the staff member heard it from outside, her training may have been to use the excuse and enter (that may be why she stuck around). A high-end property might have security, but not sure HI @ P/cola does.

Presuming it's not that, OP did one thing right and one thing wrong. It's fine to ask a misbehaving staff member to leave. But, it should never be heated or offensive in any way. That's the "wrong." The "right" is dealing with management which appears to have dealt with this by effectively comping the room.