Regardless of the correct method, it's ridiculous they went for disqualification. That's just bullying--as in "don't you challenge us or we'll show you." It would be like sending out armored SWAT teams for minor traffic violations. Oh wait, that is a thing now.
One has to understand that when it comes to safety in pro peloton and especially lately involving governing bodies being forced to finally do something, well, they are still wet behind the ears.