John 7:50

Nicodemus saith unto them (he that came to him before, being one of them), Doth our law judge a man, except it first hear from himself and know what he doeth?

Not all of the Sanhedrinists were evil men, Nicodemus being one of the notable exceptions. He had already been to Jesus (John 3:1ff) and was obviously out of harmony with the satanic spirit prevailing in the Sanhedrin. Such men as Nicodemus, and there may have been a considerable number of them, were helpless regarding the policies of the organization. The members were divided in their views and would continue to be divided, perhaps until the very end; because there is no evidence whatever that the final meeting of the Sanhedrin that condemned the Saviour had a full representation of its members or even a legal quorum. The men who controlled that body had already decided eighteen months earlier to kill Jesus (John 5:18); and, at the point of Nicodemus' objection, Satan was already in charge of the hierarchy. It was far too late to reverse the purpose of murder in their hearts.

Nicodemus apparently knew that his question would be shouted down, and that probably accounts for the mild manner in which he stated it. Anything stronger would have brought their wrath upon him.