The guys in white are very good at getting an arm hugging around the back of their opponent - which sets up throws really well (the other guys are equally not very good at preventing them doing this). Without the means to use head and neck as leverage points (understandably in competition of course) it is very difficult to prevent the opponent winning if they have an arm in this position and you dont.
They also are very well practiced at the quick win take downs - where as the opponents strike me as practitioners who dont specifically train for competitions and probably just do push hands in classes. I agree with previous opinions that this would probably include stopping short of finishing moves which are critical in this sort of competition.
This is a nice example of how serious training for this sort of competition and conditions puts you miles ahead of everyone else