How does Asimov establish that John Campbell was wrong in his opinion that it is not possible for a science fiction mystery to be fair to a reader in the same way as a classical mystery is?

Asimov established that John Campbell was wrong in his opinion that it is not possible for a science fiction mystery to be fair to a reader in the same way as a classical mystery is, as he said that:

John treated or interpreted science fiction in wrong way. In a moment of failure, he maintained that it was impossible to write a science fiction mystery. The opportunities in science fiction were so broad, he said. I imagine that what he expected was the sudden change of rules of the story and he was confused in his own thoughts. Asimov believed that it is fair for science fiction as well to be fair to a reader.