The Physics of Movies

Something bothers me in Charlie and the Chocolate Factory: When Augustus  Gloop gets stuck in the tube after being sucked out of the river, you see the tube bursting at the seams as the pressure supposedly builds up. But it doesn't make sense. If Herr Gloop were blocking the tube, then he'd also block the suction and there would be no pressure build in the chocolate at all (although I could see Gloop's head blowing apart a la Scanners if the pressure got low enough in the tube. At the very least he'd have a earache.) And if the tube DID pop, chocolate wouldn't come out, but rather air would come in.

This assumes, of course, that the gizmo works via suction. I suppose the infeed funnel could have some sort of pumping system in it, but that seems like a poor mechanical design for normal operating conditions.

My point is this: The physics of Herr Gloop's experience don't really jive for me. The rest of the movie is completely believable, though.