What I see wrong in the video is after getting the dog excited, he runs. That makes him a classic cursive target which is about irresistible to an excited dog. Then the dog nips or grabs his leg, we can't really see exactly what happened there. It is never okay to allow a dog to use their mouth on a person, but the man is training to/reinforcing that behavior.
Yes they are smart, I never thought I would have a poodle. I've been surprised at what good dog she is. The best part is they don't shed, but the groomer is a $50 bill.