It is not uncommon that sprinters gradually move to one side in their sprint and I think it is tolerated as long as they leave enough space along the barrier. Here it was on the edge for me as Naesen stopped sprinting at the moment others would probably still try to push through the gap. I can understand him however because Groenewegen did not show any intention to leave that space to him before he eventually changed his direction towards the centre again. Tough decision but I wouldn't mind dq-ing the winner this time just to teach him to sprint straight. Or even better just exchange their positions if that's possible.