I was 100% sure this would happen. Yes there are a number of ways it could have happened, but in the end they knew who had the keys. You point a gun at the person and say "tell me the password," encryption "cracked." Or you show that person a picture of their niece, father, first love whatever and then a few pictures of people you've torture to death. Encryption "cracked". Or you put a keylogger chip in a keyboard on a computer known to have the codes. Encryption "cracked". Or ... who cares. The information was high value, they knew where it was. They knew who had the keys. None of it and no one was protected by serious security.
And maybe the password was breakable. Even if he used 256 bit encryption, if he used a phrase that was too small, then, dummy. Whatever the outcome was assured from the beginning, because Russian intelligence and Chinese intelligence are the sort of people who will spend a million dollars to poison someone with polonium just to make a point.