Err.......Ok, this might be a cultural thing......but why are you citing the translator notes for the New international version of the Bible for a grammatical choice?
The translators notes mention, "The gender-neutral pronoun ‟they” (‟them”/‟their”) is by far the most common way that English-language speakers and writers today refer back to singular antecedents". The article also goes on to mention, "instances of what grammarians are increasingly calling the ‟singular they” (‟them” or ‟their”) appear three times more frequently than generic masculine forms."
The wide-spread modern usage is shifting towards "they", again "impelled by the desire to avoid sexist implications of HE", which is exactly what this particular case involved. Grammarians apparently dispute the usage. It might even come down to a stylistic choice in the end.
My point stands, as does yours.
Regards
Theo