A harness horse on the lead is allowed to drift out. What they are not allowed to do is change position to prevent another horse from passing. ie If the five horse had suddenly dived inside after a slow drift to the outside then that would be interference. Or if a horse suddenly went two places wide on a dime then that would be an error. But if a horse is naturally on a slow drift to the outside, it's allowed. I would say there is no infraction in race 11.
Also notice the head nod of the four horse in the straightaways. He's sore on his right side, thus bearing in and preventing Devaux to go wide of the four. The right side of the horse gets relief in the turns because their weight shifts to the left on the banked turns. But when they straigten back up in the stretch, the pressure shifts back to the right.
