The Hidden Blade Assassin's Creed in Depth

http://www.youtube.com/watch?v=MKrs0HyY7hg
[Front-paged by stabguy]

What if Majd Addin stopped killing people and just walked away? Well... My latest exploit does just that. I introduce to you Back to the Future exploit!

Setup
After killing Majd Addin go to the main gate of Jerusalem. Get the attention of the guards outside by killing the guards inside. Now the guards outside will try to get to you by climbing the beams. Here's a way to get them to temporarily fight you. Hang on the beam by the gate and when a guard comes he will throw rocks at you. Drop down and for a short while he will attack you before going back to the beams. If you manage to counter an attack you will glitch through the gate! Now fast travel out of there and come back.

Back to the Future Exploit
Upon arriving back in Jerusalem the gate will be open (probably because you are not under city alert). When entering you will be told that leaving the city will reinitialize the memory. Go talk to the bureau leader Malik. You will start the mission again as usual. But what has changed? When you get close you will hear the crowd talking as though the scene had just ended. Then you might hear the first victim talk. When you start the scene Majd will start saying what he last says to the first victim, and a few more things in the scene are out of sync. The scene ends with a long pause and Majd killing the first victim. As a result he falls off the stage and walks away. Because you weren't detected there isn't a distance restriction, but you can't follow him without crossing an invisible line that ends the mission. Now there are a few other ways this could end. If you don't hear the first victim speak before the scene you will hear her during the scene, and afterwards Majd will glitch partway into a wall. You are unable to lock onto him or assassinate with the hidden blade but can hit him with a weapon, which can get his attention but might also move him too far into the wall. Another way this could end is by having the second victim talk before the scene. I found that if you get away from the stage you can make more of the after-scene dialogue happen. The farthest I've gotten in the after-scene dialogue is the second victim talking. Now Majd will take a shortcut out of the place by climbing the building. I decided to end the video with an air to assassinate.

The Exploit Explained
Since you fast traveled after the assassination the area was refreshed. And by coming in through the gate you reinitialized the memory. So you start the assassination again, but the game knows you already did the mission, which results in the after-scene stuff happening before and during the scene. It's like the game thinks you are at two different checkpoints at the same time! For Majd Addin it's a tug of war between the scene and after-scene scripting. So the AI gets confused, and Majd is no longer affected by the scripting after the scene.