The fact that Horriuchi was commissioned to continue his cold blooded murders at Waco should be all you need to give credence to that claim.
That's not the way the rules of evidence work -- not even on FR...
FWIW, it is my personal belief that Horiuchi should have been executed (or, at least, been convicted of manslaughter) for that shot. The fact that he was allowed to continue his murderous career is bad enough -- even without the insult of a yet-to-be-proven (to me) commendation in the mix...