Interesting concept, but like all things, make something idiot proof and along comes a better idiot. Somebody would actually put it on a stem against the curve!
I understand the "flack" Moss describes, but his process as described, under the conditions given, in my mind, is a acceptable use for the carabiner. Are there ways around it? Could it be done differently? Yes, but in Moss's situation it is a case of an experienced climber, knowing the limits of his kit and using it to potential in a specific circumstance where the gear can properly function.
The problem I often see in climbing and rigging, is climbers will claim to know and observe the limits of choking a carabiner to the stem, follow those limits for a bit, then disregard them at convenience. Often this disregard comes from being lazy. Unfortunately, this improper use behavior gets passed on as acceptable to others less experienced/knowledgeable.
Sort of a side track, but I felt it was important to point out that all techniques and equipment we use have benefits and limitations, the "ying and yang" of kit, if you will. This becomes more and more apparent and important especially now as clever, intelligent minds develop/adopt new and different techniques into the tree climbing world.
By the way Oceans, ever figure out the answer to the last climbing question I asked you when last we spoke in person of tree climbing? It's O. K. if you don't remember. I just recently recalled I asked!
Tony