That stuff is pretty good, 30 yards of slack is hilarious.
The post about unattended weapons brings back one where I was a victim of a similar lesson;
During Underwater Rescue training, we had just exited the water, took off our gear and were being debriefed. As we are facing the instuctor, a deckhand slips behind us and turns off everyone's air. The instructor lays out the next scenario: lost diver with excessive bottom time on the wreck we're tried into, what type of search pattern and limits, then we go. To fight the initial bouyancy, you usually don't take a breath until you've started your descent, I was at about 15 feet in a head down position before I sucked on a dead regulator. The only solace was to see the rest of the group bursting to the surface, equally as pissed as I was. It was a crappy thing to do, but a lesson I will never, ever forget.