That character should not have been considered flat-footed.
Also, sticking to that rule does nothing to spoil the drama or cinematic nature of the attack, in my view. Still a creepy moment and a startled and spooked character (and, ideally, player...)- they just remain able to react because they are aware they are in combat.
Also, sticking to that rule does nothing to spoil the drama or cinematic nature of the attack, in my view. Still a creepy moment and a startled and spooked character (and, ideally, player...)- they just remain able to react because they are aware they are in combat.