He does push. I notice that he doesn't have the apprehensiveness to clam up and be absorbed in his think-tank like many Ni dominants do. I think most introverts in general grind that introverted axe until they're ready to cleave with it in the extraverted world. "Thinking before saying" would be introverted, while "saying before thinking" would be extraverted. As a result, you may see that many introverts on these forums have the tendency to pock discussions with little frequency, but with great depth, refinement, and focus. On the other hand, extraverts push the envelope with more frequency, less premeditation, and more breadth. This, of course, has many exceptions, and Z might be one of these exceptions. I think that if he is an INTJ, than his Te Se axis is akin to Jaguar's, and his introversion is only moderate. I have seen him delve deeply with the Ni "flippy paradox shift dolphin", as I like to call it, but he keeps laying down his opinion far after his introverted side has flaked off. I picture him as a fighter, just like I picture Jaguar. Someone who's always ready to shout their opinion from the highest mountaintops (in reality, it's a roof top, but don't tell Them that).
And yes, he does kick bootay, while squeezing the other.