Under what circumstances can the university council withhold Ph.D. degree?

This a famous case 28 years ago where the defense committee approved the dissertation and recommended granting the degree. The department council and the college council both approved granting the Doctoral degree to the candidate. However, the university council did not approve awarding the degree and did not give reasons to the lower councils.

What are the norms in north American universities? Under what circumstances can the university council withhold (or deny granting the Doctoral degree) Ph.D. degree to a candidate?