I've run several 4x4s in the NCAA and internationally and they always gather the 2-4 runners in the call room and read out these rules, then the officials are also very stern with the athletes when ordering them on the track. Also, when you are incoming, you normally take note of your position at 200 (because you know that's the point) and that makes it easier to position yourself for the home straight, which prevents late cross-overs that are dangerous as well. You don't wait to look for the singlet colour of your team in my experience. So i am very surprised this happened.