In this particular case, he had all reason to believe his work was being used by some to do illegal things. But even then, is that any different than the people who work on TOR knowing full well it is used to abuse children, or who work on military weapons knowing that innocent people are targeted? Should a gun seller who has reason to believe the buyer might do something illegal with their be punished for making the sell anymore than any of the tech products used to circumvent laws (from minor laws dealing with content piracy to major laws dealing with child abuse)?
Can we draw a definite consistent lines on where helping criminals commit crimes is moral, where it is immoral, where it is legal, and where it is illegal?