He had to factor in the millions of alumni and fans who weren't "familiar with the situation" as well as Tressel himself. Cut the cord without some absorption time and you've got much more of a ticked off fan base, a legend who seems not to have gotten "due process", much more potential for a Joesus-lite martyrdom/cult situation, and maybe even a Tressel who chooses not to go quietly. Besides what I'm sure was use of the time behind the scenes working out the details of separation by "resignation" with Tressel and letting him work through the stages of grief and exit with some dignity, the "firestorm" (which IMO was basically a fart in the wind in the grand scheme of things), gave the cover of necessity to do the inevitable, possibly helped other coaches know that Ohio State isn't a "graveyard of coaches" that just casually tosses its legends aside, and let the media and outsiders (and to a degree Tressel himself), rather than the administration/institution, look like the bad guys.