Portal Easter Egg - Are you dead or not?

At the last battle between Chell and GLaDOS you are trapped in a room where she is filling it with a deadly neurotoxin and you are trying to kill her. Destroy all but the last core "eyeball" in the emergency intelligence incinerator, but hold on to the last one until the last possible second. Wait at the incinerator activation button until about 5 seconds before your time is up. Then press the button and run back through the portals you set up for quick transport between the incinerator and button. Grab the last core and wait until the timer has just under 1 second left. Toss the core in the incinerator. It will burn up just as the timer runs out. Then run back through the portals and push the button again. Run back to the incinerator and jump in yourself. You will die, but you will actually be stuck in limbo! When the lab is destroyed you are back on the surface in a white haze, and the party associate will haul you away. But you never get to see the cake, core room, or ending credits. The game simply ends and you are in purgatory!