Where did this whole Vader killing for minor failures come from?
?....
Because as I recall, in the movies, the officers under his command didn't do anything minor failure wise that he killed them for.
Admiral Ozzel= The guy was noted as having failed multiple times by Vader before hand, then he comes out of lightspeed too close to Hoth, thus the Rebels were able to prepare and set up a defense with their shield.
Captain Needa= His SD was chasing down the Falcon, then lost it. The Falcon crew were critical in capture, because....duh it had high ranking Rebel members and it would also force Luke to come to Vader.
....So....where are these minor failures at?