Smacking him around is, of course, stupid, senseless, and prosecutable, but the guy is not entirely blameless himself:

from the article:
...One recent e-mail from Mirecki to members of a student organization referred to religious conservatives as "fundies," and said a course describing intelligent design as mythology would be a "nice slap in their big fat face." ...

That's like walking onto a bull's field waving a red flag.