That's something I thought, too, but everyone from the cast that I've heard says Aubry did not play a poor social game. I think we're all in agreement that Michele had the better social game, though. The only thing I can point to would be bitterness and the jury favoring social over strategic. When you look at the jury you can see cases of both. Jason and Scot are bitter people, even if they say they aren't. Just watch Cydney's Ponderosa video. It's kind of pathetic, really. From Ponderosa videos I get the sense that Julia is still playing the high school cliques and wants to be with the cool kids in Jason and Scot (plus she had a good relatonship with Michele). That's three votes right there pushing for Michele. In Michele's interview (link posted in this thread), she said she had a much stronger relationship with Cydney than what was shown on TV. There's four. Plus, even though Nick seems to be strategically inclined, he never really played with Aubry, so it's tough for him to see what she really did since her moves weren't "in your face".
So I can see where the votes came from, it's just not how I would have ever voted.
Side note, Cydney's Ponderosa video was awesome. I really like her, and I hope we see her play again. She's a down-to-earth, humble human with a chip on her shoulder.
