Caitlyn can headshot targets when she is stunned etc
Caitlyn can headshot targets whether they stepped on a trap, from passive, or netted when she is stunned and would be otherwise unable to auto attack
example: alistar knocks caitlyn up the exact moment yasuo steps on a trap- she is able to headshot him alistar knocks caitlyn up while yasuo comes to attack- she can not attack him because she is stunned/does not have a headshot ready.