English allows plurals such as “they” and “them” as a substitute for long expressions like “him or her” even when the person in mind is singular. We don’t, after all, have a gender-neutral singular third person pronoun.
Another gender-related quirk in English is to use the masculine to refer to everybody. This is falling out of style, but you still see it, such as in this Curtis, panel 1:
We have perfectly good gender-neutral substitutes such as humanity, humankind, humans, people, and so on.
Old habits die hard, though, so don’t make too big a fuss when someone uses the masculine to refer to people in general.
PS—Here’s another example of using the masculine to refer to everybody, this time from Darren Bell’s Candorville. Third panel, top line.
Interesting that he used “itself” referring to humans in the last line of the panel…