It is against the rules that are both obvious if you think
  about them and spelled clearly in AdSense agreement

Laws are also both obvious and spelled clearly. Nevertheless we need judges to interpret them according to each situation. Even with those judges in place, we still accept that some people will be punished for moral behavior, while others will walk free for immoral behavior, because a law cannot possibly cover every situation under which it will apply.

In this case, it seems to be the regrettable situation where someone is being punished for moral behavior. Regrettable, but perhaps unavoidable. However, that's as far as you should be willing to go. Trying to justify Google's actions by accusing the one that was punished of immoral behavior is not necessary and not warranted.