Their claim that pilots with lower hours perform better is based in a large part on the performance of ANG and AFreserve pilots entering the pipeline with 750 hours. These pilots tend to be top performers and not require additional training because they have been through a fairly intense selection process followed by a attrition based flight training program. Basically the AF eliminated the problem children.
On the civilian side the regionals have to eliminate the problem children or provide additional training to try and get them up to speed. For this study to be valid you would need to look at civilian trained pilots only something the RAA did not choose to do.