Let me clarify: if it comes out that she 100% lied about all of this, then I would have no problem with a lawsuit, because that would show intent on her part to intentionally try to damage him and his reputation without just cause.
I have yet to see reason to believe that's her intent here, though. I know he's saying he didn't say something offensive, but it's very easy for people to say things that don't register with them because they thought nothing of the comment, but which would register with someone else.
Of course, someone in this thread said they were there and didn't hear it the way Laura did. So, maybe she thought she heard something that wasn't said. Or maybe that person, as well, didn't pick up on something that she did. Until/unless a video of the event comes out, figuring out what exactly happened is going to be tough.