The man was part of an arranged marriage in Gaza. His wife, a Palestinian who grew up in Kuwait, lived in Ottawa and the family settled in this city.

I suspect this has a little to do with Islam (probably Shia Islam specifically.)

1. Under traditional sharia law the testimony of a women is worth half that of a man's. If the wife was a nonmuslim (not allowed under some interpretations of sharia but allowed in others) then their testimony would be worth even less or worthless.
2. Under traditional sharia law a qadi must be a man and not a women. Some places now differ on this but the fact remains that qadis in the past were traditionally men.
3. There must be four witnesses for a hudud (crime against Allah) crime which demands the death penalty. Either women are not admitted as women for such a crime or their testimony is worth half that of a man's. Regardless, a conviction for that type of crime is unlikely for a case of marital rape. Other crimes are tazir (decidable at the discretion of the qadi), diyya (blood money) or qisas (retaliation in kind) crimes.
4. The punishment for such a tazir crime would be either a fine, around 99 to 30 lashes and/or imprisonment.
5. If the matter was treated as a qisas crime then the person would be punished with equal violence but the person can settle for diya repayment which they could be socially pressured to. If the wife was a nonmuslim (not allowed under some interpretations of sharia but allowed in others) then they would be forced to settle with diya because qisas is not permitted between nonequals.
6. If the matter was treated as a diya crime then the person would be punished with a monetary fine. However, in many places the monetary payment for a woman would be half that of for a man. If the wife was a nonmuslim then they would have even less repayment.
7. Under traditional sharia law a divorce for a women can be hard to obtain and they must obtain permission from a qadi first.
8. Under traditional sharia law a man can beat their wife if they are angry with them.
9. The koran does not explicitly state that permission is required to have sex with a concubine or a wife.
10. The whole qisas/diya system that requires an heir or wali to prosecute allows for socially approved honour killings when no relation is willing to prosecute. As well, traditionally a very large amount of authority is given to parents.

This sort of stuff sets up a misogynist culture. Not sure how well this applies to Shia Islam as I know much more about Sunni Islam. Now I'm sure some people might know Moslems who would never approve of such a thing and some other people would say that this stuff isn't real Islam. However, Kuwait probably isn't conducive to a progressive world view.