It is a fact that the FBI was one of the organizations infiltrated during Operation Snow White. The FBI files have been released under FOIA and it is now a part of the public record along with the trials of the 11 Scientologists involved in Operation Snow White.
As to the claim that Scientology gave technical training to the FBI, there is no evidence to support this. When Scientology made similar claims regarding NASA, NASA denied their claims. I doubt Scientology would have any 'tech' that the FBI would want. The FBI has pioneered many techniques and trained law enforcement agencies around the world. Scientology has not.
I understand your view. I know what I typed was not something I read. It was in a discussion I had with someone in OSA or CCHR. Could well have been bullshit, or hyperbole, or outright lying and exaggeration given to me. And yes, I have seen NO evidence anywhere of such action.
Maybe someday someone from OSA or CCHR will add some data. The era was circa 1994. What programs was CCHR working on around that time? Dennis Clark was somehow connected from what I remember.