It's not clear to me that negative correlation was the finding. For example, the result does not show that teams of randomly selected high aptitude individuals

It's not clear to me that negative correlation was the finding. For example, the result does not show that teams of randomly selected high aptitude individuals perform worse than teams of randomly selected non-high aptitude individuals. From what I can tell, the only finding here is that teams with individual aptitude as the sole selection criteria performed poorly in competition against teams that had more traditional selection process. This would be an expected result for me.