Cause, then they have just impugned an honest person for a quality of work issue.

If there is actually something for them to fire him with AFTER the season, then it is negligence on the part of the school for not firing him sooner. That situation is pretty crazy.

From Sean Miller firing:

“A “for cause” firing is uncommon, especially in sports. In college sports, such a firing refers to when a school concludes that the coach has violated a specific contractual clause that normally relates to ethical conduct. Usually a “for cause” firing relieves the school of the obligation to pay the coach any remainder of the contract. The coach’s employment is typically considered terminated for purposes of a “for cause” firing only after the coach has exhausted any available appeals with the university to contest the firing. For this reason, the date when the media report a coach as fired and the date when the coach is contractually fired can be weeks or months apart.”