Why would a guy put his Facebook relationship status as "It's Complicated" when his "girlfriend" has hers as "Single?"?

Just to make something clear up front: I’m not interested in getting involved with someone while they’re in an unresolved relationship, though I am interested in better understanding someone’s actions.

Background: I met this guy at work who, out of the blue, started being exceptionally nice to me for about a week—flirting with witty banter, pointing out dumb things like the fact we were wearing the same color shirts one day, complimenting me, following me around and trying to get my attention…the works. Then, at the end of that week, he asked me if I wanted to go to a party.

I ended up backing out (1) because I was genuinely surprised to be asked this by him (we’d never talked all that much before the week this all started), and (2) I’ve always taken “partying” to generally mean “get drunk and wild,” which is not my pace. Anyway, after this I didn’t see any more flamboyant behavior from the guy, though he was still very nice to me. (As I later found out from another co-worker, he was just planning on going bowling—which I totally would have done.)

I kinda felt bad because I DID actually want to hang out with him, so the following week I asked what he was doing on the weekend. He’s in a band so he had studio time and would be pretty busy, but he asked, “Why? You wanna hang out?”

I said yeah.

He responded that we should try to hang out the following weekend; I said okay. What really gets me is what he does afterwards: this little happy dance accompanied with a “oooo…!” noise he made as if he just managed to hook up with a really fine chick, lol. (I don’t know how else to describe it.)

Afterwards, I started putting some feelers out to see if he was actually interested in me or just being friendly. A few days later he came out and told me, apologetically, that he was “on break” with his girlfriend of 4 years, which has been really stressful and complicated for him, then said he’s sorry if he’s been sending mixed signals and thought I was nice and didn’t want to hurt me so he thought I should know and was just being honest.

Okay…

Anyway, my question is: why would a guy label his relationship status on Facebook as “it’s complicated” if his girlfriend in question already has hers as “single?” I don’t know any more details about their troubles (not my business, really), but I just thought this was odd. (He’s a Gemini-Taurus cusp, if anyone cares; I’m a Leo-Virgo.)

I just think the whole situation is odd, honestly! Opinions welcome. :)