No, he didn't. A "small botnet" or Tor is not particularly useful to force you to violate the Adsense ToS by telling your visitors to click on your ads.
If it is a mere algorithm, then it is not unforeseeable, that, due to no fault of your own whatever, but malice of competitors, you can get banned, though, in these cases, I think there would be a good legal argument, not least because the google contract you sign up to is not entirely recognised by some courts, but replaced in many instances by what is or seems reasonable, as, when you sign up to the contract you have no choice but to sign up, thus, there is no equal bargaining power.
I'm sure the fraud detection system is not perfect but in this case it actually worked as designed. Yay for Google, boo for people who try to take advantage of the system.