Not as exciting as yours, but my first time and several other times through, always attacked big sis Cindy at the finale; after plenty of runs I ask what happens if you attack Sandy or Mindy first, to which they tell me, Cindy brings them back. Okay, think nothing of it and just accept it as fact. Get an obviously special group, but make it to the final boss; and for some reason everyone wants to gank Mindy. I put a 1 marker on Cindy and even say "Cindy first, she'll revive the others." But my pleas went unheard and they knock Mindy down and sure as shit, Cindy brings her back. This was about a week or so ago and none of them got the explorer achievement, so they all apparently had been there before, and while it was nice to see, I was in shock that we had to do what is essentially a newbie trap.