"It was a singular confirmation of his theories, that the judges should wish to let him go"
I am confused about the usage of "should" in the following description about Socrates, in the book The Story of Philosophy by Will Durant:
"The rest of the story all the world knows, for Plato wrote it down in prose more beautiful than poetry. We are privileged to read for ourselves that simple and courageous (if not legendary) “apology, ” or defence, in which the first martyr of philosophy proclaimed the rights and necessity of free thought, upheld his value to the state, and refused to beg for mercy from the crowd whom he had always contemned. They had the power to pardon him; he disdained to make the appeal. It was a singular confirmation of his theories, that the judges should wish to let him go, while the angry crowd voted for his death. Had he not denied the gods? Woe to him who teaches men faster than they can learn."
In "the judges should wish to let him go", what does it mean by "should wish to"? Is it stating a surprising fact?
Thanks a lot!
Happy Chinese New Year!