Ya they call the computer "The Director". They set the AI up so that the horde will wait until an opportune time to jump out and do damage to you. Apparently the zombies are going to be easy to kill.
The point's not to outlast them or even run from them but to make it safely as a team to the rescue point.
One other thing I thought was cool was that you basically get 3-4 chances before you officially "die" and you can "respawn" when your team finds another survivor hiding out from the zombies. The game sounds really, really interesting.