I understand it's a ton of dough. But I still think he made a huge mistake on the way he handled it. If I was in his shoes (and I say this with all candor), I would have entertained the original offer. Once I said no and publicly declared to CU, I'd play out the year with CU. Yes, for a year I'd make 2.7M versus 5.4M (or whatever the #'s are), but I'd keep my integrity and the likelihood of another opportunity the following year would have been very high, IMO. As it stands for him now, particularly if things don't go well in the B1G, he could flame out as a HC and be left with nothing but an integrity issue.
I guess I'd choose to bet on myself that things wouldn't go in the toilet for the additional year at CU. I'd look at the math as not a 15M loss, but perhaps a 2.7M loss with my integrity intact. But that's just me.