With the exception of a medical board, it has not been my experience to have ever seen any discharge given by a board that was better than a General discharge.
Remember, a board of officers is NOT a good thing. If they're having a board at all, it's because of some offense. The board will either find the accusation unfounded .. and the accused will go back to duty as before .. or founded, in which case, if they want him out, it wouldn't be with an honorable discharge.
I'm not saying that it's not possible, but the chances are probably better being hit by a meteorite. In 27 years, I've never seen one.
I'm talking about upgrading a less desirable discharge to honorable, which seems to have happened.
He should've gotten a discharge in 1972; instead, he got one in 1978.