Jewish Rabbi say that only non-jewish souls have the possiblity of getting destroyed?

The Mishnah (in the Talmud, tractate Sanhedrin) talks about a few Jews who will not make it into heaven. The emphasis is that the rabbi whom you mention said "could" not "would". There are evil people who don't deserve to make it into heaven. Even an all-loving God has limits on how much He will tolerate. Judaism teaches that if non-Jews live by Noahide requirements (no murder, stealing, etc) they WILL make it into heaven. We also teach that the vast majority of non-Jews CAN make it into heaven.