I absolutely think so. Although cheating is a hurtful thing to do, there are many things that could lead to it that don't necessarily mean that they don't love the person. Humans (men specifically) aren't wired to be monogamous and it takes a great level of control to stay faithful to one person. This is not an excuse for cheating, don't get me wrong, but sometimes biology takes control and urges cannot be controlled.
Another thing is that perhaps the person seeks emotional support from their significant other and is not longer sexually attracted to them. It's not necessarily their fault for having those feelings, but again cheating isn't the best way to go about it. Despite the act being something that should never be done, the reasons for cheating have to do with a lack of communication and poor coping skills.
Since love is such a complex emotion one might disagree that a person could ever cheat on someone they 'love', but I believe that it happens more often than people think.