It's not that simple. Real cheaters will react, and devise counter strategies to whatever you are tying to do.

I can understand that Google is strict about this, that's their core business, CPC and conversion rate are what makes them the best advertising platform in the world. They have to protect that fiercely, even if some unfortunate users are thrown under the bus along the way.

Is it possible in the AdSense scheme to set up multiple accounts? It seems if he'd had an account for the YouTube site, and another one for his sailing stuff, he'd at least have kept his money maker.