Are you sure you fail the mission by killing Niko or Patrick? I didn't even think you could kill either of them in the first place since you take off in the Buzzard. Grand Theft AJ 20:39, November 30, 2009 (UTC)
It's Niko and Johnny, not Niko and Patrick.
Just after the cutscene when Luis takes the diamonds you can see Niko on the ground floor who's fighting cops, you can shoot him and kill him which will result to fails the mission. Nostrein 20:48, November 30, 2009 (UTC)