How did the Fuhrerprinzip work at the Nuremberg Trials?

The Fuhrerprinzip was a defense commonly used by top-Nazis on trial at Nuremburg. It stated that all the decisions made regarding Nazi Germany were made by Hitler, and to refuse to follow these orders meant death.

This defense rarely worked because the jury could reason that not all the decisions being made in Germany were made by Hitler; his associates like Goering, Himmler, and Bormann could (and did) make decisions that cost lives as well. Therefore, the blame did not fall squarely on the shoulders of Hitler, the responsibility for the horrors of the Holocaust and the War were spread out evenly among the Nazis.

The judge also ruled that human rights come before following orders, and there are no exceptions to that rule.

There were a few Nazis acquitted, however, but not because the defense worked. It was because of ill health requiring hospitalization or (in the case of Martin Bormann) if the defendant was tried in absentia.