Bette Midler sued Ford for hiring an impersonator. She lost in the circuit court and won on appeal. The fact pattern in the appeal was that Ford had explicitly asked their actress to "sound as much as possible like Bette Midler". That's exactly what didn't happen here: not only did they not ask the actor to impersonate SJ or her character from "Her", they didn't even mention SJ. The actor used her natural speaking voice.
However knowing saying such a thing would be problematic they would be looking for workarounds. Considering they did giver her directions and the end result was closer to ‘her’ than the voice accesses natural voice they didn’t need to ask for a specific impersonation for people to make the connection.
I’m thinking of a number, bigger, no smaller. Keep playing the game and the end result is arbitrarily close to the number you’re thinking of.
The search space for generic seductive female voice is huge and they happened to end up with one that objectively sounds like someone they tried to recruit. They can’t argue random chance at this point.