Again, these suits (at least in the States, I don't know what you do in countries whose laws remember the Middle Ages) are based off the concept of damages, not permissions. Selling blackmarket Simpsons T-shirts is clear damage. Making free bootlegs of Star Trek bloopers is still damage because Paramount could conceivably sell those in a compilation tape. Neither of these cases is hypothetical. Using a prop in a render is not the same as giving the prop away. Period. The maker of the prop would have to demonstrate that there was a profit potential in releasing images of the prop that you were cutting into. And the moment they try that, the question of why they put the prop in a usable domain (e.g. sales) comes into play. Can't have it both ways. Just because something is in a set of terms given with a file does not make terms legal. Any contract, like a will, is contestable, and the more absurd the terms the less likely they'll stand up.