om = bărbat, not just ”human”? Wiktionary says that the use of om as an alternative to bărbat is rare today, but perhaps the course makers want us to learn that we might encounter it in old books etc?
If somebody would say that sentence to me in everyday life, I would assume it's about a man (specifically, an adult man). Otherwise, I'd expect them to say "O să apară o femeie..." or something similar.
I m romanian and it wouldn t because everyone uses om as barbat qnd rarely as femeie for exemple: O sa vina un om sa repare robinetul. U would expect a man not a woman otherwise u would say o sa vina o femeie.