Over at the official Killzone 2 site, Guerrilla games developer motherh666 was asked about Killzone 2 A.I in which he replies that, the "A.I Was Toned Down Quite A Lot" so they could properly demonstrate the game to the press.
Guerrilla Games - Developer motherh666:
"Yes, it was toned down quite a lot. When putting games on pods it is more important for us to show as much of the game as possible, rather than making the life of the person playing it difficult. The demo was fairly tame."