Just fly far from beta 4 ...that make the NPC fly far from beta 4 too .... ( the NPC chase you ) After that .... kill the NPC ------> i recommend you use missile because faster and then ... mission complete .. and 1 more .... i think the dead of beta 4 is not a glitch ... that is the point of the mission ... ----> safe beta 4 so if you fail to protect beta 4 .... he will DIE