At the start, Cartman says he's not bothered about seeing the T & P movie cause "the animation's all crappy", but throughout the rest of the film, T&P are referred to as real people.

Also , in the scene where Cartman has to turn the power off at the USO show, he is wearing a backpack. He gets scared by Kenny's ghost and runs away to see Kyle and Stan in the audience, and when we see him again, is backpack is gone. Then, when the boys meet The Mole after he has been bitten by the dogs and is dying, his backpack has returned.