> Create a mission with 3 playable units
> Name the units p1, p2, p3 respectively
> *Create a trigger that gives a hint when !alive p2
> Repeat * for p3
> Create a trigger that gives a hint when !alive p2 && !alive p3
> Set various timers on each trigger so you are able to see each hint in turn while testing
> Play the mission, kill p2 and p3, watch the hints (works as expected...)
> Quit out, play the mission again, except this time turn off one of the AI, doesn't matter if it's for p2 or p3
> Kill p2 or p3 depending on which one you left AI in
Result:
The trigger fires for the unit that dies, but the 3rd trigger which should fire when both units aren't alive doesn't do anything.