Call of Duty 2 and Call of Duty: Big Red One were advertised on TV with some impressive footage. But it wasn't taken from in-game action. Take a look at the commercial for yourself:
Do you find it misleading? The ASA sure did. Activision claimed using such pre-rendered footage was "common practice." That was then, of course - now you'll see "Not in-game graphics" or "Images representative of gameplay" written at the bottom of the screen.
We do have to ask, though - when gameplay can look so spectacular straight out of the console's wires, why not show game footage? You know, just for once?