Several have already hit on the correct response. The professor should retain a legal *team*, and file a truly enormous lawsuit against the university, definitely before they fire him.
To start with, this will throw a monkey wrench into their plan to fire him. Their lawyers will insist they put the firing on hold, because any actions they take against him will be regarded legally as retaliation, and thus could double or triple his punitive reward.
And the student who was the focus of this should be brought in as well as a party to the suit, to prevent the school from taking any adverse actions against him as well as to maybe pay off his student loans with the reward.
He needs to be fired first. Otherwise he has no damage claim, and so no basis for a lawsuit.