Considering how quickly people are apt to start accusing Microsoft as being OMG EVIL, I would think that to avoid bad press if the kid wasn't legitimately cheating they'd be extremely fast about releasing a mea culpa and complimentary llama to smooth things over. Because they haven't, and because they released info to the kid's mother, I doubt they're "hiding" anything. It's probably more a case of, "Look, lady, we have proof that SOMEone, either you or your kid or someone else, illegally modified that account. We're keeping this out of the media, because we don't want you to start a shitstorm about how it's been faked, or how we SHAMED YOUR CHILD by publishing it. Someone on your end screwed up, so just accept it." But of course she won't because she'll smell money.
I had a kid in my class growing up who was so autistic he could barely function on his own. Went everywhere in a wheelchair, had to have a helper feed (and presumably bathe) him, didn't make eye contact, couldn't communicate, spent a lot of time just hitting himself... my point is that if this kid is in good enough shape to play all these games and issue coherent statements to the press, he's a lot luckier than other people who apparently have his condition. Get a playstation or something and start again.
I never understand achievement appeal.