Mr. Answer Man says: It means that he needs to grow a spine.
Quibbling over shades of definition is one of the unfortunate things guys do when they're ashamed of their feelings, in this case being afraid to tell the hard truth that he's not in love with you. Worse still, it often occurs when a man is trying to have his cake and eat it too, e.g., stay in a relationship while not allowing it to advance beyond his current comfort level.
The antidote to such doublespeak is to hit it with a little truth of your own and then see what that reveals. If his philosophizing on "love vs. in love" were met with, "Fine. Call me when you're in love," Mr. Wishy-Washy might find his backbone pronto. And if the call never comes, so much the better -- you're now free to find a man who loves you enough to be in love with you too.
Go to the Mr. Answer Man message board to find out what everyone else has to say about those three little words.