He found the address in the source code of the ransomware, any researcher could have found it. He even said himself that when he found it in the source code and saw it was unregistered he registered it to see what would happen. As it turned out it stopped infections from occurring.
Not to say that he isnt the malware writer but your use of quote marks makes me think you have no idea about what happened and havent looked into it, just made some "wild assumptions".
Not to say that he isnt the malware writer but your use of quote marks makes me think you have no idea about what happened and havent looked into it, just made some "wild assumptions".