Comp, thanks for posting the vid, it's not clear, but sans interference call, wouldn't the throw into the runner be ruled a dead ball and batter-runner be awarded the next base? I don't agree with the non-interference call, tho.
I bought one for my DD at that age. There was only one brand available and it came with an instructional CD. She never cared for it and never used it. The size of the puck replicates a 12" ball. At 8u it was way too big for her to use. Now that she is throwing a 12" ball, it is still never...