1. Create a group in the editor.
2. Create a trigger, make it big enough so that no members are outside of it, link it to the group leader and change the activation from "vehicle" to "whole group", and "not present". In the 'On Act' just type 'hint "Trigger Activated"'.
3. Create your player and preview the mission.
4. Kill a member of that group and notice that the trigger activates even though it shouldn't.