As if any stone needs to be cast. One needs to cast stones [undertake active action] to promote, not to deny a promotion. Denial of promotion is absolutely passive activity.
When one becomes that high profile and obviously groomed for advancement, then what would normally be passivity, would be interpreted as retaliation.
And any Secretary of Defense would not want to become involved in appearing to be a party to such a politically indefensible action, he has nothing to gain.
But that is just my opinion.