Climbing IS a dangerous sport, in which people who do not learn from the mistakes of others do not survive.
This time, I was lucky and survived.
It was a quiet night at the gym. We had decided to climb vertical. There were many of us, including a noob friend of mine. He is very skinny, so Marian's old harness did not fit him, and as such I gave him mine. My new harness (birthday present, thank you, friends!) has an idiot-proof buckle. Regardless, I gave him my harness and explained in detail why we double back a buckle and what are the consequences of us not double backing a buckle.
For those of you that have no clue as to what the hell it is that I'm talking about, here's a picture from the interwebs (you need to replace that flabby tummy with a six pack if you want to know how it looks on me. Also, my harness is much less colorful, but I digress).
(Photos from here)
As I was explaining things to the noob, I must've stopped buckling my harness, which was like the one in the picture (but less colorful, remember).
I then tied in, and started to lead climb a shorter wall at the gym. It had been a while since I had led, so I was, as usual, scared shitless.
I reached the top of the climb, clipped the last quickdraw, and, while holding the last handhold, told my belayer to tight (remember, I was scared shitless, so letting go without being tight was. not. an. option). My belayer got the rope tight, and, as I lowered my weight on the rope (still holding the tile), I heard a massive velcro tear-like sound. I glanced down and my harness was hanging from my quads. I was standing at the top of a climb, with my harness going down to my knees and my left hand (my weak hand btw) holding on to a medium jug. Dear friends and family, I did not swear. At all.
To my credit, I did not freak out either, but also did not do the right thing. Actually it was, but there was a better solution.
So. I started to buckle my harness while holding on to the handhold, and reached step 4 in the photo. It was getting really difficult to get to step 5 with a single hand. However, had the shit hit the fan, I could have held the loose end and get lowered like that (I did not think about this until later). At this point, my belayer started shouting at the top of her lungs (and she has a pair, bless her): GO UP AND OVER! GO UP AND OVER! Which I eventually did. The shorter climb at the gym has a ledge on top that was used a while ago for teaching abseiling. I went up and over, met one of the gym staff who took me down on the emergency ladder.
So. Things to note: thank fuck it was an easy climb and I did not fall. Had it been the roof (which I tried later in the night), I would have probably been disabled (not dead mind you, as the height is not significant to kill you, sadly).
But, most importantly: do all the checks. Look at the knot, the harness, the route, the quickdraws, the backcliping, your feet with respect to the rope while you climb, the rope with respect to your hands, everything. Do this EVERY FUCKING TIME.