it seems a lot closer than people would guess I suppose. Perhaps Jordan having the weight advantage and ability bully Lebron on the post. Although a lot of these comments were made in Jest, I wouldn't casually say James Young could. He did beat Michael Kidd Gilchrist not too long ago
http://www.usatoday.com/story/gameon/2013/02/15/michael-jordan-beat-kidd-gilchrist-charlotte-bobcats-nba/1924059/
Personally, I'm very, very skeptical of that Kidd-Gilchrist game (though if anybody has more details I'd love to hear them).
I know Jordan's competitive, but he's also pretty much an evil genius. And when you're that competitive, usually your evil tactics increase to compensate for your declining abilities. Did he challenge MKG after a grueling 2 hour practice? What did they play to? How many rules favored Jordan (Who got ball first? Winner's out? No Posting up?) I wouldn't be surprised to see Jordan challenge him after practice, score quick before MKG even realized they were actually playing, then Jordan says "game's to 3 (or 5, something short), I have to golf in 20 minutes" (some excuse for it to be quick with no rematch)...
Plus unless this was the first day of training camp and MKG comes in as a naive college kid, he might have learned not to show up the boss under any circumstance.
If it was legit, I think we would have heard of the re-matches, something along the lines of not only did Jordan beat him, but he beat him everyday before and after practice for a week just to prove his dominance. When I hear only about one game, I think Jordan either hustled him or he chose not to show up the boss.
Of course those are all just theories, maybe Jordan did whoop him legit, my money is still on James Young though.