Oh, those are on the list as well. I didn't say Solich, Bo and moving to the B1G were the only mistakes. I said they were among them. The point was that 3 of the big mistakes, actually more if we're including Pederson (so, 4 out of the 6 big mistakes), were all on TO. Great head coach. Horrible AD. The best and worst thing that ever happened to Nebraska football.
Therefor, THEE biggest mistake was letting TO hang around the program too long and foolishly thinking that just because he was one of the greatest head football coaches of all time, that somehow qualified him to also be a good Athletic Director. Michael Jordan was the best basketball player of all time too, but that didn't make him a good executive for the Wizards.
Solich - TO
Pederson - TO (sort of)
Callahan
Bo - TO
B1G - TO
Riley
Side note - I actually don't consider Frost among them. Obviously didn't work out, but it was the no brainer hire that 10 out of 10 programs would have made. Easy for hindsight to be 20/20 on it now, but he was the hot commodity as the next up and coming head coach and nobody can honestly say they could question that hire at the time it happened. He checked all the boxes and then some. In fact, I'm not sure that a lot of Frost's failures weren't due to meddling from the old TO regime. But that's a different topic.