Safety tip: When both climbers are tight and level around the tree at the bottom of the tree, the v front bars's edge is pointing downward. Thus both edges will not bite inward toward the tree, and can slip slightly. When up a tapered tree, both climbers are at a great angle downward with the V edge pointing straight into the tree, but they are not tight hugging into the tree and are loose around the tree, thus there is no weight leverage, that your body applies, to force the bite into the tree. Thus, both climbers can give you a slow ruff ride down. If one climber does bite, it is a terrible jar to the body. Now, the safe way on a hard slick tree is keep both climbers in the middle of 0 degrees (level) and 45 degrees downward which gives both of best worlds for no slipping, even seen on the metal pole, that is why. Around 20-30 degrees angle, my TL has never slipped. Outside of that, I have had either climber slip an inch but did bite. If the foot climber slips, your weight setting down will force weight on the TL and it will likely bite hard into the tree. I cannot see a person sliding down a tree in a falling state unless both climbers broke. Please explain to me how one slides 15 feet in theory. The only way is to have the back bars so loose where both climbers pointing almost straight down, thus no weight leverage, Or so tight, the edge of the V cannot bite, I can see that happen. Otherwise, not logical. Please explain in detail for others and myself how the slide happened. There was a cause and likely a failure of the operator, wrong adjustment or no body weight applied, or broken equipment. Thank you in advance for explaining for all to learn, to slippinlipjr.