I'd take this with a grain of salt since the FSI also offers training to LE agencies, so the study seems to be a bit self-serving: Your training isn't adequate, you need our services."
"The Force Science Training Division makes training available that will educate administrators, trainers, investigators, attorneys, officers and other legal professionals on Force Science findings and will help facilitate the application of Force Science concepts during their investigations, training and work in the field.
Force Science training classes are available for agencies to purchase. Generally, our two-day program is recommended, but in instances where that is not possible, we do offer a one-day option. There are no restrictions relative to more than one agency working together to purchase and fill a Force Science class. In fact, many agencies work in tandem to bring the program to their area. For details on pricing and the program, visit the Training Information page." - Force Science Institute website
My opinion might have been different had this come from a more "neutral" organization, or confirmed through and peer review and/or other groups conducting the same experiment and getting the same reults.