I actually had to do one about eight years ago. Guess that ACRT stuff was good for something.
Just left a job to go look at another one and my main groundy called me saying our new climber was un-concious and hanging upside down in the tree. I was only about six blocks away so I told him to call 911 and get my gear next to the tree, it was no where near any power lines so I already new it wasn't energized.
After breaking every traffic law in the book, I got there and drove my truck strait through their landscape and into the backyard right to the tree, got my gear on and made my way up to him. At this time you could hear the sirens coming. Didn't know what was wrong with him but he was un-responsive, hanging upside down and foaming at the mouth.
Just went through this aerial rescue stuff so it was still pretty fresh in my mind. I put a lowering line on his d's and cut his line with my hand saw. My guys were lowering him to the ground when the EMS got there and placed him perfectly on the stretcher. EMS guy said that was amazing - where'd you learn how to do that? They would have never been able to get him outta there..
SO - turns out he was a f#####g junky having some kinda drug fit and passed out or fainted.. Guess I can partially blame myself for not spotting it sooner, and letting him work that day when he always seemed "not right" to me... Ended up canning him..
Sorry for the derail there 2tree, just wanted to share my experience with it..