Originally Posted by Chazboski
Got the glitch following your guide the last time. Zombies just run up and start attacking as normal essentially. The game forgets its a stealth mission.
2 things trigger it. You run/walk faster than the game likes, or Amy is seen. It's surprisingly not a random glitch. Happened to me a bunch at first when I was banging my head against my desk. The fact that those damn Zombies have an infinite sight line is idiotic and mostly why she gets seen easily as she wonders around a bit (not specifically when you see the splitscreen cutsene).
It annoyed the piss out of me. I ran through it a 2nd time on easy though in under 15 minutes failed twice because of those hawk eyed Zombies.