I would agree with the general consensus that they should be allowed to fire the professor. I would also think (and hope) the professor would feel a bit uncomfortable anyway in that environment. Maybe we'll see him on the next Catholic post of those who have swam the Tiber.
Why should an evangelically-friendly Catholic (Campion, correct me if I am wrong, but is there not a discernible strand of orthodox Catholicism that is evangelically-minded?) be uncomfortable at a serious Evangelical university?
For instance, when the professor signed on to teach at Wheaton, when the issue of inerrency came up, he agreed with it, but taught "that the Bible should be read in light of 'authoritative traditions,' an example of which would be church councils. " This is my own position too - that the Early Church Fathers, the Councils, and particularly the early creeds are the lens through which the New Testament is to be interpreted. I would have thought myself comfortable at Wheaton - at least until this article.