Knowing Moriarty's name was not precisely reassuring in John's book.
This was another American, though. Shawn hadn't mentioned what nationality his boss was, but what were the odds of two Americans in Cardiff knowing enough about James Moriarty to ask John questions? Sherlock would no doubt have yelled at him for jumping to conclusions without facts, but he was in this situation because Sherlock had disappeared on him. He only had his own instincts and abilities to work with.
"I've had the misfortune of meeting him, yes," John replied, crossing his arms over his chest. He should be cautious, but he really wasn't capable of pretending to like Moriarty. He wasn't sure he could be neutral about him. "Know anyone who claims to be a psychic?"