Re: 99.995% is impossible
The figures sound perfectly reasonable to me.
99.995% of the internet is cat videos and only 6% of terrorist beheading feature kittens, so the test dataset was the entire internet and the algorithm is: (drumroll)
return false == IsCatPresent();
(More seriously, given any non-random algorithm that isn't completely one-sided, I can obtain any error rate I want by fixing the test dataset.)