No, it's more than a nitpick, and I think the correction is the wrong one. The study says that there was a Y-chromosome bottleneck, consistent with a very small number of males compared to the number of females. The "was the result of brutal warfare" part is speculation, not the result of the study.
It is probably a reference to the conclusion part of the paper, simply because it's an obvious hypothesis. It's not necessary that men died like flies, they just didn't procreate, but that's not mutually exclusive. Eitherway, it would be the result of competition with a social aspect.
