Honestly I'm not sure this was handled correctly, there is a difference between delaying when the fight is lost, and merely just waiting for the chance to strike, it sounds to me like defenders were honestly trying to win this battle in the only way that they could, by waiting the time out and then killing the attacker.
Obviously in 99% of cases this wouldn't work because of cav, archers, etc, hunting them down, but in this case it sounds like a legit, if not overly exciting, strategy.