He hasn't shown Human Path abilities. By that logic Minato can enter Bijuu Mode since he has half the Kyubi sealed inside him and Nagato can use Perfect Susano'o since Rinnegan gives access to all jutsus.
Also your logic is terrible.
being able to bring forth all ninjutsu.
One who gains the Rinnegan has access to a multitude of abilities. On its own, the Rinnegan allows the user to see chakra, including otherwise hidden barriers such as the one which surrounded Konohagakure.[12] The holder of these eyes have the potential to completely master all five basic nature transformations that form the basis of ninjutsu.
He couldn't have taught him if he doesn't know them.