Pretty sure the Leonhard to Fickell pivot was as simple as Fickell wasn't interested at first, then he was. When you have the chance to hire that guy, you do, even if it means a hard choice to pass over a sentimental favorite.
All the reporting seemed to think UW was planning to hire Leonhard. There's every reason to believe that was what they thought...until Fickell expressed interest.
He may not work out; Leonhard may become a superstar (and may never forgive McIntosh for passing him over), but the decision isn't hard to understand.
Reasonably confident it had absolutely nothing to do with the backup quarterback not getting the offense to execute on 1st and goal from the five at the end of the Minnesota game.