I have no evidence to support it, but the internet is made for people to make wild guesses and claim they have sources. I admit I have no sources.
But, if I did, my source would tell me:
Lincoln Riley talked to Stoops, probably a month or so ago, and told him he was approached by USC and it was looking promising. He and Bob and the AD had meetings and Bob told them if Riley left he would come back. The deal was made. That's why Stoops could squelch all rumors about him going to LSU or UF or anywhere else. It was believable.
So, when Riley finally accepted the offer from USC, the picture played out perfect for all involved. Riley could truthfully deny he was going to LSU. He had a perfect smoke screen. All the focus was him going to LSU, virtually nothing said about USC.
OU was set. They didn't have to start doing back door searches. They had his replacement.
They can wait until the week of the bowl game, before or after, and announce, "After an exhaustive search we determined Bob Stoops is the best man to lead this program."
(How'd I do? You believe my source? He's proven to be as reliable as 90% of the other sources people have.)
but I will say this. If he had to depend on his TV job to make a living, he would soon find himself on the welfare line. He doesn't project any sort of charisma or bring much to a broadcast, not nearly as much as a former Head Coach with his pedigree would suggest.