It is obvious the OSB would fare worse in that study since it looses holding power faster and in greater magnitude than plywood.
I don't like the idea of nailing solid wood to OSB, but trying to get feedback on if it might work, will work, or if it will fail.
I know tackstrip nails don't hold as well as I'd like, and 1/4 inch staples from my Senco gun don't grab as good either when shooting down underlayment.
So if he want's nail down wood, he ought to add 1/2 inch plywood first to be sure?