I think I need to caveat this with, I could not care less if we are Nike or Adidas. I buy most of my UM clothes from Homefield Apparel or companies that go more vintage in styles. Genuinely don't care. With that said, I will throw out one other possible factor.
@Rellyrell mentioned that Nike has their standard structure of a contract in the form of smaller base and bigger contingencies based on sales. This is not just from a monetary perspective to disincentivize other schools asking for the same. Companies stick to their one format of a deal for a whole bunch of reasons, not the least of which are legal, finance, accounting, etc. are all organized based off of that one format for efficiency, both internally and externally.
There are companies that when they look to sell subsidiaries will out of hand reject anyone that will not do an equity deal and instead insist on an asset purchase, even if the asset purchasers will offer more money. Won't even entertain it because they have spent a LOT of time and money organizing their departments in a specific manner.
The assertion or thought that Nike would automatically want to match the terms of Adidas's contract if they could save a million a year or whatever is misguided from a business perspective.
I happen to agree with you about the school's legal department at the time holding significant responsibility. Look at the number of issues we had during those years just with athletics that wound up getting out. Shannon's contract termination, Golden's contract termination, Arkansas St., etc. God knows what didn't get out or make the press athletically, let alone with the rest of the school. The entire culture of the school had a clear quality oversight issue, and it is probably why a guy who ran Deloitte was brought in to fix it.