We're seeing the same thing but describing it differently. I rewatched one of the rear angles from the BTN broadcast, and once RBY secures the ankle with both hands, he reaches down for the foot with his left hand, his palm to the ball of the foot, wraps the fingers over the side of the foot, and pulls. Now, in that wrapping of the fingers, at least his pinky and ring fingers cover/grasp the corresponding toes, while the others are over the metatarsals.
Based on a review of the
latest rule
book, I'm not seeing anything about grabbing of toes in and of itself that can be construed as illegal. The applicable question in RBY's pulling of the foot (with some toes included) is as Askren described it -- i.e., whether he elevated the foot while doing so to force the limb (knee joint) beyond its normal limits of movement (see pg. 51, paragraph 1; and pg. 84, illustration 31 for twisting knee lock). It was pulled laterally, which one might argue allows the opponent the option of shifting his hips to accomodate the pressure, and it was therefore not called illegal.
Now, I'm not doubting that DeSanto felt pain, thought he was injured, and/or was indeed injured, but I just can't see an argument for an illegal move based on examples provided in the rule book.