First, notice he did not say "follow me." He realized he was but flesh and fallible. Hence, the standard is Christ who is not fallible. The scriptures provide evidence that the apostles were fallible and are not the absolute standard. We are not called "apostolians" but "Christians"! Why? Because Christ is the only absolute standard to follow.
Key here os that paul stated to them that so much as i am following jesus and obeying him, be imitators of him, which implies at times even paul was not found obedient, but ONLY Jesus is the perfect One to emulate!