Q 90

A character gets near an lying-down enemy that he believes is helpless to perform a coup de grāce.

The enemy, however, is playing possum and not helpless. Since a coup de grāce is a full-round action provoking attacks of opportunity, the lying foe takes advantage of this to strike the character.

Since the character cannot perform the coup de grāce action on a non-helpless foe, does that mean his actions are wasted this turn? Or can he still make a normal attack?