Since Trace was so polite not to mention why the lost and unconscious diver drill was so memorable, I'll tell the story.
We had entered the catacombs near the ear, continuing our own line, and just as we were coming out the other end, Trace signaled me to stop and blindfolded me. After he came back it was: "Buddy - Where"? As I start searching, still reeling out, I realize where we are and even see the main line in the distance.
My buddy was hidden behind a boulder somewhere right of the catacomb exit and he was 'unconscious'. After tying my reel to a rock, I get on top of him, holding the regulator in his mouth with my right, manipulating his buoyancy with my left, and start retreating along our own line. I assumed that taking the easy way out, going to the mainline, tying my reel in there, and exiting would have led to questions like: "How could you be sure what that line was and where it went?"
For Trace, this was very amusing. For me it was very hard work, not ever having enough hands or enough space in the catacombs. And for my buddy it was a very agonizing ride of either being banged into rocks or being showed forward through gravel. After the debrief I swore to myself to never overthink an exercise again. Instead of asking "What is the most effort the instructor could expect from this exercise?" I will ask "What would he do in my fins?".
Always apply the KISS principle.