I have absolutely no proof to support this but I try not to spook them too much while they are pipping and coming out of the egg. One reason for this is one of the main ways babies die is by drowning or tangling up in their umbilicus. To me the more times they squirm around in the egg the more likely it is that one of these things may happen. Another reason is that I have noticed babies that I mess with during the hatching process tend to be a little more skittish towards me once they come out.
But they are professional snakes... so it's probably fine.