If as you hint he was known and used, AR 25-2 makes no allowance for that. He's still in very serious trouble and should be prosecuted as anyone holding a security clearance at the level he was at would have to be.
The government would not bat an eye to quickly doing it to me as a retiree and government contractor or to an active service member. I expect, nay I demand no less for some staff puke Sybyllian, Military, or contractor in a rear area desk job.
Once more - the Pentagon is saying that they don't think there is a mole NOR WILL THEY LAUNCH AN INVESTIGATION!
You know what that tells me? There is no mole and maybe Russia was working in conjunction with the American plans.