Judge Harris went onto explain that it had to be clear that the defendant's actions were not consented to by the victim, and asked, "How do you determine that without the victim?" (Byron L. Warnken, a professor at the University of Baltimore School of Law, posed this question to a Sun reporter: "What would we do in a murder case?")
My understanding of the law here, incidentally, is that once the elements of a crime have been established "beyond a reasonable doubt" (which they were here), then the burden is on the defendant to show why there was a good "excuse" for the actions (i.e., this was consensual S&M...outside a gas station).
But yeah. As The Nation puts it, apparently "Some Domestic Violence Victims Like Being Hit."