It wasn't an enviable position for Watno, and I certainly don't hold any ill will towards him, which I also immediately told him after the challenge was done. I don't think he needs any particular reason for choosing Iguana, he just had to pick one of us, you know? I've spent most of the game in different tribes with Watno, and I was exiled for most of our time together after the merge, so maybe they just had a better opportunity to develop more of a relationship together, actually having open communication and all? Or maybe it was just random. I didn't read all that much to it, to be honest, although I must admit I was hoping he'd pick me because I had the unused power left and all, being "in a stronger position in the challenge" if you look at it that way.
But, alas, Iguana was just as deserving. The whole challenge was more kingmaking and luck than anything merit based anyways, I really don't feel all that bad about not winning. The necklace is shiny, of course, but hopefully I'll get my chance to wear it later.