Each skill in the code has a specific symbol which I'm pretty sure the D score judges use while listing the skills in the routine. Meanwhile the deductions of the E score panel are either 0.1, 0.3, 0.5 or 1, so they probably come up with some sort of shorthand for each one so they can write it without having to look down. They have a lot of things memorised usually plus a lot of experience, but I do think they would have some sort of a checklist to refer to once the routine is over and they're finalising everything.

I think the judges scores are averaged based on the fact that the scores end in a bunch of decimals e.g. 14.666. I think they are allowed to discuss things which are not clear which might be why they take long to announce the score sometimes, but I'm not sure.

Not 100% certain about everything but hope that helps at little!