You have to dig not to find copyright-infringing links at the root of TORRENTZ.EU's index.
At yet the statistic on Google's summary page suggests that TORRENTZ.EU is primarily --- no, overwhelmingly --- a non-infringing site. And that is the reason the statistic is there: to put forward that argument.
We don't have to agree on the policy debate here, but let's at least call spades spades.
I still think it unlikely that anyone is gaming that metric. It might be a bad one for whatever reason, but I can't imagine that anyone has been gaming it given that nobody knew of it until just now.