on that third demo, they run through the hallway and kill god of war. he then respawns, and james hears the respawn sound, and then there are footsteps, after which he goes around the wall and shoots. when he comes around the boxes on the other side there are 3 guys there. he didn't know they were all there, but he knew one would be from sound. i didnt watch the first 2, but i did watch the sourcedemo from dust2 and didn't see anything.