I cannot be wrong, because I have stated clearly I do NOT know what Long did or didn't know. If as you say ST players spend a lot of time going over the rules, then one team is the exception: Wisconsin.
Anyhow, it was very obvious that the return man did intend to return the FB after he picked it up...(would he even pick it up if it wasn't to return it? why would he do that?) And at that moment (when he was standing already with the FB in his hands in a running position) the unblocked NU players (all FOUR of them) were still a good 5-10 yards away...yes I am sure. So, what are players taught in that situation? (the return man after having made some type of waving signals, has picked up the FB and is VERY CLEARLY getting ready to return it, whatever signals he may have made).
Should the coverage team just let him go ahead and return it, trusting that the officials will call the return back, or should they go ahead and tackle him? Would they get a penalty for hitting a return man who after doing some sort of waving has picked up a FB and is standing in a running position with a clear intend to run back the FB?
I do not have the rule book in front of me, but I seriously doubt that anyone on the coverage team would be penalized if they tackle him in that situation (whatever waving he may have made).
To make my argument clearer I have attached below another shot that shows the position of the FOUR unblocked NU players when the return mans is ready to take off with the FB (that Wisconsin punt return team is real good, right?).