Honestly not sure what the answer is at this stage.  I'd like to see him get some support for whatever mental disorder he's got going on, but I doubt that's going to happen.  The problem is, he knows where the limit is and he won't cross that line.  But he'll be as much of a disruptive nuisance as he can up to that point.  If you dare utter one of his trigger words, he's straight in with the same misleading nonsense stuck on repeat forever. 

All we can do is challenge the dishonest stuff, even if it means doing the same infuriating dance for the rest of our time here.  It gets tedious, but at least it keeps him somewhat in check.  Eventually, once you've debunked all the lies, he just resorts to semantics and wordplay.  And by that point no one is going to be convinced by what he's saying anyway.

Keep up the good fight (and keep him out of Development and Technical Discussion).