Thank you, that answers the question. It's not a sportmanship question, it's what's the rule.
That's right. I remember an issue in a WPBA event where the player who was on two fouls didn't hear her opponent tell her, so the WPBA created a rule that the player must acknowledge to her opponent that she heard it. A simple 'OK" was was acceptable.
Makes sense, actually. I highly recommend that leagues and tournaments adapt this.