Have we yet to see the documents ourselves? I still smell a trap, so not taking anyone's word until I lay eyes on it myself. You prolly should, too, but not all of us seek the entire truth.
Or just waiting for a bigger bite before setting the hook. I feel this is more trolling by him. Appear to be hiding something so the opposition goes nuts. No real reason to hide it, but no real reason to release it, either. Make 'em crank out some bullshit, up the ante, then raise. Only then do you lay your hand. I'm sure he made damn sure his taxes were legit, but I don't doubt that he capitalized on some loopholes. My kids happen to be my employees as well.