It's even worse than this. For the system that profited on all 30 series, he used a 1SD profit target and a 5SD stop loss. And he did make thousands of trades, with many losses. It's hard to read this blurry image, but it looks like he optimized on those two parameters:

With #OptVar1 50 and #OptVar2 10 corresponding to the 5SD stop and 1SD target. So it could be an issue of curve fitting, where he just kept optimizing until he found a set of parameters that worked.