It's stupid for WND or anybody else to repeat this kind of loose allegation. If the student received death threats, let him collect the documetation, take it to the police, demand an investigation, and --- if a perp is found --- press charges.
If not, it can be assumed that the student is just alleging death threats because it makes him look like a Persecuted Rebel Boy and Christians look like belligerent snots.
Just apply the "Cui bono?" test. I strongly suspect the student is doing a Tawana Brawley.
And as for the professor: what jaw-dropping imbecility.
From PZ Myers, what do you expect? His blog's name, "Pharyngula", adequately describes his apparent mental stage. He has a hollow nerve cord (and probably a tail).
Yes, I imagine the “death threat” business was made up out of whole cloth by this student, who should certainly be disciplined. What evidence has he given to support his accusation? Of course, decent Catholics would be greatly upset by such blasphemous action, but a death threat would be extremely unlikely.
As for the professor, anyone might fly off the handle and say something stupid in an unconsidered moment. Then all he need do is apologize.
But that is not a possible defense in this case. First, he posted these insults on a public web site, which means that he acted deliberately and with intention to offend. Second, he repeated them a second time when he was rebuked and asked to apologize.
I think they should fire this sorry bigot, who is clearly unsuited to be teaching young people in a reputable school or college.