"They" is commonly used as a singular third-person gender-neutral pronoun in English — so much so that it's often unconscious. I glanced through your comments; you used it yourself just yesterday [1]:

> Anecdote time: a friend from one of the nation's major universities was involved in a road authority funded study to evaluate the safety impact of newly installed speed cameras at several intersections. [...] They found there was none.

[1] https://news.ycombinator.com/item?id=18532386

Edit: after I replied, you edited your comment to add the caveat "except sometimes in 3rd person". "They" is always a third-person pronoun, and there are no criteria that would make it acceptable only in a subset of situations.

Edit 2: now the caveat is gone. Can you just reply to me rather than changing what I'm replying to retroactively?