This is disgusting.
Does this girl not have any brothers, a father, or other male relatives to pay that punk professor a "visit"?
Believe me, if this crap had happened to any of the women in my family, they would find this guy floating facedownward in the Mississippi river, or in a vacant field somewhere, with several large caliber holes in him.
Actually her boyfriend is a very solid 240 or so with an appearance that would intimidate any man who saw him coming at him in anger. I'm not sure, other than the fact that his girlfriend is apparently very frightened of what the perp might do and the fact that he's a Christian what is keeping him from acting as you suggest.
It would be awfully hard to resist doing so.