I don't think that's what these researchers are saying. I think they are saying more along the lines of: "Hutchins has shown that he is a security researcher through his work on wannacry. As a security researcher, he probably has researched other problems as well, possibly including Kronos. The fact that he was arrested with little to no evidence could be showing that the DOJ is willing to arrest people who have copies of virus source code on their computers, even if they only accessed it for research purposes. In fact he may have updated Kronos code or written some part of Kronos as part of research to validate a hypothesis or test a theory. Such actions are ordinary actions for researchers, so this puts at risk most computer security research across the world."