Even Maimonides said a Jewish physician should not treat Gentiles if he could get away with it. And other scholars have said what this rabbi said, for example that if a Jew comes upon a Gentile at a river, he should not throw him in to drown him, but if he is already in, he should not pull him out to save him. BUT THERE ARE THINGS WE JUST DON'T TALK ABOUT, AND CERTAINLY DON'T ENCOURAGE. Example: in the Christian Bible, in the Greek, in its true translation, Paul talks about "the Jews who killed Christ" but we expect Christians not to publicize this and not to use it for incitement. So the rabbi should treat what is written in Torah or by revered Jewish scholars of the past.
17-year-old Palestinian killed by IDF on Friday laid to rest near Ramallah (Haaretz)
from the article: Police release rabbi arrested for inciting to kill non-Jews