Some info on Wikipedia about over revving the engine...

"Consequently, it is impossible to "over-rev" the engine with the throttle alone; a downshift from a higher gear must be involved. A typical "over-rev" can damage the oil pump, commonly disintegrating the lobe ring, resulting in damage similar to the picture at right. The oil pump is the Achilles heel of the 2ZZ, though incidents are rare and usually occur due to fault of the driver. Even the briefest period of oil starvation is usually fatal to this engine design."