With my IU law degree and dime-store logic in hand, here's my take:
Kevin Wilson had a checkered start at IU. He was told in no uncertain terms that he needed to change.
Everything had gotten better. Personally for Wilson, and on the football field.
Things were going so well that in January, 2016, Wilson was signed to a 6 year, $12 million extension.
In October (or so), one of the serious behavior issues re-appeared. Glass had an independent investigation done, which fully corroborated the allegation(s).
Wilson, who could have been fired for cause and received nothing, or challenged the cause and received all $12 million, instead chose to resign and accept $542k.
If Wilson thought he would have successfully challenged the potential "fire for cause" decision, he NEVER would have resigned for a $542k settlement.
IU had a fantastic choice in the wings, and made it happen immediately so that on-field momentum and recruiting would not greatly suffer.