The rabbonon may have qualified the
halacho l'ma'aseh today, but I am pretty sure that to break shabbos to save a gentile life is, in ideal
d'Oraiso terms, prohibited. The concepts of
pikuach nefesh,
sakonos nefoshos and putting oneself in physical danger or considerable risk for a goy, may not even apply.
Needlessly to say, this runs
totally contrary to the modern egaliatarian humanist mindset, and is considered unacceptable to even many Orthodox, it running against human nature.
But the Torah is not human, and part of the test is that since Matan Torah, there are now
two species of human beings on Earth: the Jewish Human and the Gentile Human, and the continued existence of the universe depends on that separateness and distinction being maintained, even if unpleasant.
Once it becomes blurred, there's usually a nasty bodycount on both sides!
Can someone elicit a definitive
Kahanist Halachic answer from the (former?) Kahanist Minhag Eretz Yisrael 'posek' R.David Bar Chayim on this subject, as since the
kitniyos "scandal", he seems to be moribund.