P.S. Yuna took the ice last and judges knew the scores of all others;
The judges had heard each skater's total scores announced. They're not allowed to write them down. They wouldn't remember all the totals from one skater to the next.
one judge gave Yuna 134.09, which is less than Julia’s 135.34.
No judge can think "I think I'll give Yuna 134.09." Judges don't give total scores. They score each element and each component as they see it -- and maybe they bump the scores up or down a little if they're actively trying to manipulate results.
They are never informed during the competition what levels were called for the steps and spins.
They don't know until after the program which jumps were officially called as < or << and get lower base marks, or whether any elements will end up not counting at all.
They'd have to be human calculators to keep track of which jumps the skater has done; what the base marks are for each element, with second-half bonuses and/or sequence penalties as applicable; what the 70% base mark is for underrotated jumps; what the values of the positive or negative GOEs for all the elements are (since for most elements +1 doesn't add exactly 1.00 points and for even fewer does -1 subtract 1.00 point); what the factored PCS are worth (since for ladies they're multiplied by 1.60 in the free skate); and also keep track of any deductions for falls etc.
Nor do they have any way of knowing during the competition whether other judges are using a higher or lower standard or wider or narrower ranges for everyone's PCS.
No one can do that math in their head in real time, even for the values that they are able to know while they're scoring. At best they could estimate likely totals for their own scores combined with likely base marks. But they could easily be off -- perhaps by several points if the tech panel nitpicked the levels or the judge forgot to take into account one particular rule.
If a dishonest judge wants to mark skater A higher than skater B on all components whether she deserves it or not, and to always give A the highest justifiable GOE and B always the lowest, they can do that. But they can't control whether the total of their PCS and GOEs for skater B combined with the tech panel calls will produce a total higher or lower than the announced averaged total for skater A. It is not humanly possible.