What are the parameters of the mitzvah not to teach a non-jew Torah? What should one do when a non- jew says “the Torah says you can’t do ___” and it’s false, can you refute them?
It is permitted to answer a non-Jew who asks a question, and it isn’t considered teaching him Torah, since it isn’t in a permanent, organized way. Therefore it isn’t included in the prohibition, not to teach them Torah We see numerous times in the gemora that non-Jews asked the Tanain and Amoraim question and they answered them.
See Avoda Zara 30a, Babba Basra 10b, Sanhedrin 90b, Turei Even Chagiga 13a, Toldos Noach 10-14.