I’ll tell you my personal opinion about this.
Editors are not always good. They think they are, but they are not.
Their educational background, their speech habits, their age. How attentive they were at school, how good their school was, how do their peers speak, how educated was their family, how much they have read in their lives, how much they use internet chatrooms and fora, how deep their understanding of the culture of the original language … all play a role. Sometimes they’re just lazy.
Way to fix this:
There’s none. Since they don’t know there’s a problem, they won’t do anything to fix it. If you tell them, you are the bad one and they resent you. They may leave the team with ruffled feathers.
They sometimes let things slip.
Even the best editor is only human. Because they were tired, it was late at night. Because they wanted to finish quickly and then start dinner for the family. Because there’s no time or willingness (for an unpaid job) to go through episode three times. Because they are foreigners.
I consider myself a good editor with a good knowledge of English if I may say so myself, sensitive to things that don’t make sense or sound weird. Yet, at the end of the day, I’m not a native English speaker and there are some nuances (prepositions or a turn of phrase) that Korean subbers use and I don’t think of correcting.
How I compensate for that?
I create myself a safety net. A native English person either before me or after me. When I’m General Editor, I usually work with a native CE so the responsibility is hers, no problems. When I’m CE, I make sure the GE is native. And, for good measure, I often ask a Viki volunteer who is a professional editor in real life, to do post-release editing - that is, check again to catch anything I might have omitted. I go through each and every one of his corrections (after all, as CE, I have the ultimate responsibility): some of them I might not agree with, if they change a nuance of meaning. But I study them carefully and try to think of how I can make it so that he doesn’t have to correct that again in the future episodes. Yes, these instances are few. But if I can avoid them, why not?
Brain auto-correct. There is this phenomenon that our brain tends to auto-correct small spelling mistakes and thinks it’s reading the right thing. There are scientific experiments for that. You understand what you read, even with the misplaced or missing letter, and your brain automatically sees it as complete and correct. Quoting from a website:
Here is a brief sentence that has intentional misspellings. Can you read it?
Tihs is a smaple snetecne to tset yuor brian’s abiltiy to corrcet mitskaes!
We bet you could read it, couldn’t you? See? Your brain helped you to read the sentence — despite the misspellings!
So how does your brain do this? And how does it do it so easily? You didn’t even have to think about the misspellings and figure them out, did you? Your brain just did it automatically.
Scientists believe that the brain’s ability to make sense out of misspelled words — and to do so automatically and so quickly — stems from the fact that most proficient readers don’t read words one letter at a time. Instead, most readers recognize entire words at once by seeing the first and last letters of the word and combining that information with other important information, such as the length, shape and content of the word.
So, as long as the first and last letters are correct and the other letters that make up the word are there — and the mixed up letters are not many or not far apart — our brains can make sense of them quickly. This allows us to read quickly and efficiently without getting slowed down or tripped up by misspellings.
Read more here
Now, this otherwise very useful function is not good at all for us editors! We have to willingly set it aside to find each and every spelling mistake. But some will undoubtedly slip. And sometimes they slip for two people!
How do I fix that?
I usually tell Other Language moderators that, if they see any spelling, punctuation or formatting mistakes, to please let me know in Team Discussions. And they do! There are some of them who are very helpful in that, and send me a list for each episode they finish editing. Thus there’s a whole bunch of other people as an extra safety net.
Of course I don’t know about other editors. What I told you is what I personally do.