I've been a reader her for a few years, done a little editing and I've been working on my own stuff to eventually post. So I was unpleasantly surprised whe I started two new(to me) serials in the same day that were not tagged with a content warning but both had water sports / golden showers in their first chapter. I could understand a minor omission but something like that is bound to be a major issue for a lot of people. I personally will no longer consider reading material by either author because of this.
Has anyone else come across situations like this? Do you think it was an "honest" mistake, and if so, how could someone have it be so prominent in the story and not have a tag?