I think his assumption is that the owner wouldn't want to "out" themselves as they are on the lamb from tons of mortgage back payments. Once the owners emerge from "MIA" to try to get him off the property, the bank would sick their lawyers on the owners.

So in this case, it's a matter of "I dare you to come clear me out from your house - but if you do, here are some banks that would be really interested in your current phone number"