If you use the "allowed sites" feature and make sure your active site is not on the "allowed sites" list everything will look normal to the attacker, but since you won't make any money from the ads, you will not cause harm to the advertisers, and so your account will remain safe.

Third party services such as statscounter.com provide free resources which allow you to track and observe the source and nature of your traffic and will help you isolate the troublemaker.

It is undoubtedly frustrating to experience a sabotage attempt, but you should appreciate that Google always puts the advertisers' interests ahead of the publishers -- they are after all paying the bills.  Since we are suppliers/vendors to Google, it is our responsibility to manage and maintain a safe environment for the advertisers on our sites; we can do this with some common sense practices.

if someone is determined to take you out despite the advice here and you cannot stop the problem on your own, then Google rightfully will not want you as one of its customers.

(PS I know how frustrating this stuff is -- I went through two weeks of hell when someone out there in "disabled publishers" world decided to take me to his level a couple of years ago.  I learned plenty about the limitations of the AdSense system, and I suppose, some of its strengths, because I'm still here today.)