In this instance there was a "third man" with whom the two (attacker) brothers were coordinating. These kinds of criminals want a definite return on their investment for the risk they're taking.... So far, all of these incidents that I'm aware of, the criminals knew for sure that the target had access to at least "X" amounts of funds.
Some guy with a BTC shirt, who knows how much he *actually* has... Although I agree, I wouldn't wear it in public.