Hate to say it, but I don't think the aide (or Webb) has anything to worry about. The media will bury this story deep, so today will probably be the last we hear of it. After that, I'm sure that Webb and Harry Reid and a few other democrats will have a "friendly chat" with the Capitol Police and the DC courts, and some sort of technicality or procedural error will be found that allows the charges against Thompson to be quietly dropped, and Viola!, case dismissed, nothing to see here, please move along.
These are democrat senators and their consiglierges we're talking about. The laws do not apply to them.
I agree with everything you wrote....but I am sure his staff today realized that Webb will never stand by them.