No True Scotsman

Love is many things to many different people. To suggest there is some kind of simplistic duality wherein any manifestation of bad behavior against another person completely negates the positive or nurturing things that person has done is, at that very least, to minimize the value and strength of love as a complex emotion.

Let's look at a more common example: adultery. Many people commit adultery to spice up their sex life, or because they are unable to withstand temptation, even though they know it's wrong and would hurt their spouse if discovered--it doesn't necessarily mean they no longer love their spouse if they cheat on him or her. Again, people often twist their morals into knots in order to avoid cognitive dissonance in such situations. And more appropriate to your point, there is such a thing as spousal rape, where, once more, the offender can justify it in their own heads (e.g. 'We're married, so you OWE sex to me any time I want it.') It doesn't mean the rapist doesn't love the person; it just means that sometimes their selfish needs take over.

So, really we shouldn't be focusing on how we define love but rather the offending behaviors themselves, because just because the offenders may love their victims, it doesn't make their actions any less heinous.