Just need closure - what does it mean when someone does this?

[john]

I used to work with her, there were times when I kinda liked her, stopped working with her a couple years, and a couple months ago I defriended her on Facebook (I started flashing back to times when it was apparent she just wasn't that into me, when she had blown me off at times). Anyway I was with a friend the other night at a restaurant and she happened to be working there, she went near us, waved briefly and talked very briefly. She asked me where I was working these days and I told her and said that it would make her want to kill herself doing that. She mentioned how she was much happier doing her current job. I said that her job seems more interesting than mine and then she said cya later basically. To me this means absolutely nothing but if I defriended someone or they defriended me I would try to avoid interaction with them at all costs.