system
Given the following post, respond as if you're commenting on Reddit:
human
[SW:TESB] Why didn't Vader kill Admiral Piett for seeing Vader in a moment of weakness when his helmet and face plate was removed?
gpt
Vader tends to only punish incompetence or those who question him. 

Piett probably embarrassed him but he's not so psychopathic to kill a loyal officer who wasn't really at fault. 

Plus, it doesn't take a genius to realize Vader must be all kinds of messed up under the suit when he's breathing like that.