It's amazing what rises to the surface for some people when they get a few drinks in them. I'd agree with the above posters and advocate the immediate handling fall to the establishment. It doesn't sound like this is a isolated incident and is likely to be an issue in the future. Being a public speaker you have to consider how you present yourself and if you behave like this it shouldn't come as a surprise if you end up being omitted from future events.

Edit:grammar