I thought it was an interesting defense, and I agree with parts of it. I did find it an interesting point he made, though, that Shmi seemed to have no desire to escape her own slavery. For a while, I thought he had a point, but then I realized that the movie actually did address why that wouldn't be possible. The slaves have that chip in them that can be activated to blow them up if they escape. Remember that Anakin was working on a sensor to find where his was? I wonder if he ever found it? It seems to me that he didn't have time to get it removed before Qui-Gonn took him away. You'd think, that if Watto was really pissed for Qui-Gonn beating him at betting that he'd just wait until Anakin was on their ship and then just blow him up out of spite!

Eh, but I don't know. Watto seemed to have a soft spot for "Li'l Ani," so maybe he wouldn't do that. But if Shmi had tried to make a run for it... well, the world would have more Tusken Raiders, now wouldn't it?