Arch Nemesis - Waypoint Separation Eagle Strike
http://www.youtube.com/watch?v=JEsMzhnIvbA
The target in the Arch Nemesis mission of Bonfire of the Vanities is programmed to stay on his balcony. If you try to move him off the balcony, he will attempt to return there (i.e., the balcony is his waypoint). It turns out that he cannot climb back up to his balcony if you bring him down to street level. Once at street level, he cannot reach his waypoint, so he will be unresponsive. I use this as an opportunity to position him for an eagle strike from a nearby viewpoint tower.
Clear the area
Start the mission by clearing out all the guards in the area. This ensures that nobody is left behind to interfere with the waypoint separation and eagle strike. Note that the air assassination of the 2 bodyguards is initated from a specific location so that the target is not accidentally killed.
Waypoint Separation
Don't throw the target directly to street level. The height of the fall is sufficient to kill him. Instead, grab and throw him onto the roof, and then move him over the edge of the roof so that he falls to a lower level roof. Immediately tackle him on the lower roof and throw him down to street level. This completes the waypoint separation - you can freely position him now.
Eagle Strike
Use the shingles on the roof of the viewpoint tower to guide your aim. I run directly parallel with a line of shingles. Grab the ledge and air assassinate.
All I ever do anymore is attempt each mission using the superblend exploit. I did this mission successfully a few times. You should try a superblending video with him but taking out each guard before you hit him. It's harder than it sounds. I'd do it myself but...no camera. 
So it's a fleeing target, but he has to get to the balcony before he runs away? That's definitely a flaw that can be exploited. 
no, he doens't flee. its really weird. he just tries to return to the balcony. the guards and target on that balcony automatically forget that they've seen you once you leave the balcony as well. that is ubi's way of ensuring that the target wouldn't follow you away from the balcony. im not sure why they programmed the mission this way.