This is why it's being discussed.
New Jersey Family Judge Accepts 'Sharia Defense' to Excuse Spousal Rape - Associated Content - associatedcontent.com
From the comments section of the link:
The judge's ruling involved a restraining order that the woman requested after the couple was divorced. The argument involving Sharia Law was that the ex-husband felt justified in assaulting her while they were married, but was not likely to assault her again after they were divorced. It had to do with the risk of further assaults -- nothing at all to do with excusing the actual assaults that had occurred while they were married (for which the ex-husband still faced charges).
King James Bible: The wife hath not power of her own body, but the husband: and likewise also the husband hath not power of his own body, but the wife. ...
An appellate court soon reversed Judge Charles' decision, but the idea that any American judge, no matter who appointed him, would actually rule that Sharia law was a defense for committing a felony should be grounds for impeachment.
And this is the one of the reasons for separation of religious beliefs from law.
Upon further reading it seems this judge based his decision on to deny a restraining order for the divorced couple:
"The trial judge got it right. A restraining order is not a punishment for past behavior, but designed to prevent future behavior. Since Defendant believed that in his religion he has the right to rape his wife, he did not violate his religious beliefs by doing so. However, now that he is divorced, it would violate his religious beliefs. Thus, the judge found that past conduct pre-divorce is not an indicator of future behavior.
I do not support rape on religious or other grounds. But the trial judge?s ruling did not say that a man can rape his wife if his religion allows it. The judge merely considered the Defendant?s religious beliefs in trying to predict future behavior to decide whether a restraining order is necessary."