Don't think it would be a ban. I just logged on and the Crimson map pack was available for me to download despite the fact I did not purchase a LE, nor did I have a map pass.
I did go ahead and buy the map pass before downloading just in case, but he's telling the truth. He didn't cheat or anything, it's just available for free.
I just wish to warn everybody that if you do this Microsoft will ban your console once they have it sorted out. It's happened before, it will happen again.