The couple in this article was not legally a couple therefore only a last will would have been legal here. The claimant has no chance in fighting for his inheritance. The fact that the judge/court ruled that only male/female are considered a couple is of course from the dark ages. I don't think a "romantic relationship" gives anyone the right to claim an inheritance, only a wedding certificate or registered partnership can do so.
Law expanding definition of terrorist activity passes first Knesset reading (Haaretz)
from the article: Court rules gay partners are not couples under Inheritance Law