Reducing residents work week, increases or decreases medical errors?

In 2003, the ACGME recently set standards restricting residents from working more than 80 hours a week. The purpose was to provide residents with more time to rest and study for the improvement of training as well as decreasing medical errors resulting from fatigue. The University of Mississippi conducted a study that found that after the enforcement of the 80 hour week rule, residents have been performing much less procedures, resulting in less experience and training.
While it seems ridiculous to most of us to work 100 hour work weeks or to go days without sleeping, the findings of the study suggest that residents are not getting enough exposure to observations and training to become an expert physician at the end of their programs. While the standards were set to reduce medical errors due to exhaustion, who is to say that the medical errors will not increase due to insufficient training. Both concepts are very much debatable and are open 80 hour work week to study and experimentation.