When Selena had rung her apartment bell, the girls were admitted – or rather, the door was drawn in and left ajar – by a colored maid with whom Selena didn't seem to be on speaking terms.
Source: J. D. Salinger – Just Before the War with the Eskimos
Is it necessary to use past perfect ("had rung") in the above sentence? Recently I was here advised that according to grammar, when there's a short action right after another short action, we use the past simple for both actions, e.g. "When I opened the door, children run in". I think that this pattern we can apply to my examplary sentence. Or not?