Right; the premise of this conversation is the edge cases where this isn’t obvious. For the vast, vast majority of places this entire conversation is moot because the addr:city such as we know it in OSM isn’t in question, and can just be easily gained through a spatial query.
This isn’t a tangent, I think you’re driving at the very heart of the matter, and this is a great example of where you really do need to distinguish with that addr:city tag. Given there is a distinct numbered street grid in San Pedro, even though it doesn’t have its own municipal government, I would presume anybody in the LA area would distinguish San Pedro from the rest of LA because otherwise you wouldn’t necessarily know if you meant an address downtown instead.
All a “9-1-1 address” is is the address you would give a 9-1-1 operator in an emergency. I would presume if you called 9-1-1 for an ambulance and they asked where you were, if you’re in San Pedro you’re very pointedly going to say so, and they’re going to know precisely what you mean.
