In Scottish Law, if the jury cannot reach a guilty or innocent verdict, they may return a verdict of case not proven. I think this is the verdict I am returning here.

Darcy turned round to see Elizabeth when Bingley pointed him out. Therefore Bingley was on in front of him and Elizabeth behind him. He then broke eye contact with Elizabeth and addressed Bingley. So, he must have had his back to Elizabeth. This would be normal precautions to prevent someone overhearing you at a Ball, I would submit.

There fore I would suggest that Darcy did not deliberately, or through reckless thoughtlessness ensure that Elizabeth heard his remarks and has done nothing to apologize for.