I hope he's right.
For whatever it's worth, Marquis Daniels worked with Price before the '07-'08 season. That season, he set a career high in 3PT%, but a career low (to that point) in FG% and FT%. Since that time, his numbers haven't really changed appreciably from his seasons prior to working with Price. In other words, it hasn't seemed to really help, and Daniels' shot has never really improved.
I have no idea how much time each player put into practicing their shot, how many hours they worked with Price, if other consults were (or are) scheduled, etc. However, it's one example, at least, of Price not being a difference maker.