Fair enough. I just haven't ever heard or seen anything factual to back up that statement.
Well this may not help you because I don't have a link to it or documentation of it.
My uncle coached TX HS football for over 30 years. He spent a few of those years in a district with Stephenville. Through those years along with countless clinics he got to know Briles. Anytime we get together as a family I always end up glued to his every word while he recounts old coaching stories for hours. I've probably heard some of them 20 times and I still love them. On more than one occasion he's told me about Briles, one phrase in particular.
He said he had a fantastic football mind, was an offensive innovator, worked extremely hard, was funny, smart, and had a way with words. He was very complimentary toward Coach Briles.
But this is the line that always comes up when he gets going on Stephenville games which always leads to Briles;
"If I had something I knew he wanted, I wouldn't walk in front of him in a dark alley for fear I'd wind up with a knife in my back."
He heard that (or something similar) from a coach he worked with. That guy had spent a few years on Briles' Stephenville staff.
That's how every Briles and/or Stephenville story ends.
*Don't even ask who my uncle is or where he has coached. That's his business. This story is anonymous enough I don't have an issue posting it.