Prove they were clean. Apply the same standard to yourself. You can't either. Some of the "red flags" you mentioned were that his family wanted to get paid, others were his attitude.
I'm not claiming SLU cheats more than anyone else, or is more egregious. If you want to believe you are the only clean team in major D1 basketball go ahead. Sounds an awful lot like UK fans who say Cal is clean because he never got caught at UK.