What is she dropping? If a hotel employee says something to management about not liking what someone said, they can move that someone. They are not required to do an investigation. Mike's problem is with his employer.
Exactly. Neither she, nor Marriott have taken any legal action. They apparently didn’t like what he said to that employee so they exercised their right to have him removed.
For example, and this is only an example:
I check into a hotel. At the front desk I say something to the agent about coming up to my room later, to some degree of lewdness or offensiveness. She, being an employee and with other customers in the area, keeps her poise and finishes checking me in and we part ways amicably. Afterwards she reports what happened to management and they decide they won't have a guest here talking to an employee like that. So they have me leave. No pressing charges, just we don't want you here.
I'm on a work trip so my employer gets wind of me getting booted from the hotel that they put me up at. They tell me to go home for the week. Again, no pressing charges, legal action, or even having me fired. Just we can't have this nonsense here at this busy and important time for our business.
Now I can sue the hotel and the woman but they didn't do anything wrong. In fact I did by my boorish behavior. As you say I may have an issue with my employer for their reaction to it but that's a different matter.