A Social Dilemma

Let's just say you're a member of a Condo Board. The previous manager didn't do any work, he may even have stolen from  you (I'm still looking). His negligence cost the association many thousands of dollars in uncollected payments. His lying about his qualifications and then giving (bad) advice led your board to approve a half-assed plan that left 1/3 of the building without hot showers. You are now spending tens of thousands of dollars to fix this. You suspect, but cannot prove, kickbacks from the previous contractors.

He talked bad about each Board Member behind their backs, de-trained the staff, left without notice after writing himself a check for unused vacation (which is against our by-laws). It was not enough to be actionable.

Now he's back in town. And isn't he friendly? You see him all the time!!

What do you do?

So, the kick ass. That's my first choice.
I think verbal abuse is my second choice, but it's not natural to me. Much.
The cut direct--you know, where you refuse to acknowledge their presence--is my next choice.
So far he has been getting stiff greetings to his most friendly overtures. I am sure this is very funny, and I come off as very gauche.
However, am I supposed to pretend he's not a lying snake in the grass?

My etiquette is at war with my principles. Please advise.

photo from spreadshirt.com