Just to add something relevant to the USA academic dismissal landscape - and probably relevant to other countries also.
Some universities are the property of, and operate under the control of, one or other church. For example, the USA has 244 catholic church governed universities - of which 60 are Jesuit governed. There may be other universities in which certain departments (e.g. theology, divinity) are under the auspices of one or other religious denomination.
It has been known that professors of theology have been dismissed (and their dismissal upheld in courts later) after making utterances in conflict with prevailing church dogma. In Germany, Hans Kung was on the point of getting booted out of his job within the Institute for Ecumenical Studies after sharing his views on papal infallibility and celibacy. Luckily, in his case the University of Tubingen stepped in to secularize his Institute within the university and save his job. But others have not been so fortunate.
Obviously, such removals of tenure may only occur in departments over which the denomination has authority. So a Jewish lecturer in economics in John Carroll University cannot be summarily fired for referring occasionally to the Vatican as "a terrible waste of money". He could however find himself subject to a cold war campaign amongst colleagues envious of his talents or courage who would make affectations of orthodoxy in favour of the university management.