I think we may be reading too much into the involvement of U.S. Integrity. I went back through the 13-page letter to see where they were mentioned.
The NCAA notified the B1G about the cheating on Oct. 18th. The B1G then had a call with tCun (Ono, Manuel, and their legal rep) and discussed it, with Petitti saying he told them he had to make this information public. The next day the B1G talked to U.S. Integrity, who confirmed that the scam should be made public. After that was done, Vegas could decide if they’d yank tCun games from their boards. It’s possible they were only involved in the discussion about whether the scam should become public knowledge.
There doesn’t seem to be any indication to me that U.S. Integrity was involved any earlier than than that, so I don’t think they were involved in exposing the cheating,