Obviously you are correct on the date of enrollment. Mea culpa.
Also, to your point, I seem to remember something about the memorabilia rule being new, or at least a new application of an older rule, or something to that effect... meaning that it may have been perfectly understandable that players thought the gear was "theirs" to sell and the rules education on that specific violation hadn't been updated.
Listen, conspiracy theories aren't perfect, okay! They have their holes. But they also have their allure...
I still can't get my head around the car dealership thing. Didn't those dealerships have signed memorabilia hanging in their showrooms ? Even if there was an investigation, I imagine it went something like this:
Tressel: Terelle, you didn't sell your gold pants to drive cars all over town, did you? I mean, that would be really bad if you did.
Tressel: Okay, case closed. No violation. Now let's get down to business. Somebody pull the tape from Michigan's latest practice.
Or something like that. In reality, it's more likely that a coach with his season on the line did JUST enough to check the boxes and fulfill his duty of investigating the incidents.
The conspiracy theory, though, is so much sexier. I really want to believe that Tressel's "straight-laced" persona is just that: a public image. That it's just a schtick. That he's just like every other coach out there scratching and clawing to get a ring, sweatervest or not.