For me, the entire report can be distilled down to these three statements:

According to TSA, the program was deployed before a scientific validation of the program was completed in response to the need to address potential security threats.

However, a scientific consensus does not exist on whether behavior detection principles can be reliably used for counterterrorism purposes, according to a 2008 report of the National Research Council of the National Academy of Sciences.

Because of these data-related issues, we reported that meaningful analyses could not be conducted to determine if there is an association between certain behaviors and the likelihood that a person displaying certain behaviors would be referred to a law enforcement officer or whether any behavior or combination of behaviors could be used to distinguish deceptive from nondeceptive individuals.

Or, to distill it even further - Waste, Fraud, and Abuse.