Wasn't he in charge of or in the higher end of the government led agency to investigate these things? He doesn't seem to be a nobody just saying he saw things, it was his job to investigate it for the government?
And if the Inspector General is involved, along with the dudes lengthy time in front of congress, surely it's likely that evidence was presented to higher levels of government that the public still can't see legally. I get that this may be a psyop kind of thing, but writing it off as 'he didn't see anything' seems like an incorrect position to hold.