I am only posting this because he already got DQed but the Penn State runner also flinched before the gun was fired, he gained no advantage from it and if anything lost time because he could not push out from an ideal position
Anyways, I wouldn't have DQed him for cutting in going into the turn - same goes for the 3rd leg of the 4 x 4. It is the nature of sprinting in lane 1 of a 200m track with 40 meter straightaways