It's really the wrong question.
GBD is *grace* *based* *
discipline*. One of the tenents of it is a lack of phsyical and arbitrary punishment, but that's not what defines it.
If it's permissive, it's not discipline. The problem is that people hear (or observe) a lack of traditional punishment and they filter all normal child behavior through their own issues. A gbd'ed child who pushes is seen as "out of control" while one who is spanked is seen as normal and in need of a spanking.
GBD is firm, non punitive and relationship based.