The answer, (R' Tzvi Hassid of Yampala teaches) is that the Talmud agrees with the Ariz"l and the question in the Talmud was actually, upon which klaf (parchment) are HaShem's tefillin written? The passukim put forward are the klaf, not the passukim written on the klaf. Interesting.
Reb Zusha explains one level further: Bnei Yisrael are the klaf of HaShem's tefillin. So if, Has v'Shalom, The Jewish people were not tzaddikim, then HaShem's tefillin wouldn't be kosher, since tefillin need to be written on kosher klaf. So therefore, clearly, since HaShem's tefillin are (obviously) kosher, Bnei Yisrael are tzaddikim.
[Menorat Zahav (Parashat Bo)]