I thought he was off in the vid; but it could be the stilted gait. It's also hard to evaluate because of this markings; he's always going to look uneven in front with the different colored forelegs.The gait is so stifled, he looks lame because of it.
trust me I didn't touch his mouth. Lol.It looks like the rider is trying to "hold" the horse into a frame instead of riding him forward into the bridle. A head set is the result of proper haunch engagement and cannot be produced by a tight contact alone. I would ride him on a looser contact, initially, and encourage him to move much more forward and increase the contact when he is more forward and balanced.
It is too difficult to determine his way of moving from that video. The rider is hampering his stride too much and the footing will not encourage the horse to move freely.