WHOA! No, No, NO! You're missing the big picture. This is fucking BRILLIANT! Magnus Carlsen level strategy! Take note: I'm thinking the caller knew it was a realtor and prospective buyer, but did this to deter one or both from returning. It's a dirty move, but you're well within your right as a "concerned citizen" (next-door neighbor) to call in "suspicious" individuals. Honestly, with Fair-Housing Laws, something like this is really your only defense.