Actually Isreali marriage laws are the leftovers from . . the Ottoman empire. something that was never changed by the British Mandate.
Each religion in Isreal in in charge of the marriage laws for their own communities, and very very few religions have any sort of interfaith procedure of any kind. And if the Religious authority one belongs too says,sorry you can't marry that Christian chick, then they cannot marry as Israel has yet to institute civil marriage.
What does this have to do with the issue at hand ? If a Saudi woman travels abroad to Toronto, takes and passes a driver's ed course and manaages to get a driver's licenses, when they return the authorities won't pull them over and say
"Oh you have an Ontario Driver's license ? I'm sorry move along, move along"
In Isreal as stupid as their marrage laws are, a Gay couple can leave the country, get married, and have that marriage recognized in Israel...( We should be using this to get gay couples to get married and spend their honeymoon in Niagara falls ) Now if a gay couple in Saudi Arabia tries that, I doubt that will go over very well.