I don't see the problem here. They have an apartment they need to get rented. They tried to pressure you by very likely lying to you, just as district attorneys lie to possible criminals. Whether the statement is true or not, you choose not to succumb to high pressure tactics. That is the end of the story. If everyone behaved as you did that method might change but the salesman is never going to be on your side, as I am sure you know. You are using the reverse practice on him by letting him know that you are not going for it. You, of course, are telling the truth.