Ah, the usual efforts to escape the problem. Happens all the time. Most people are cowards to face hard problems even if the problem is only hypothetical.
It is not the point if this particular scenario would arise or not. It is that sometimes reality forces you to make a choice between two “unpalatable” options. The situation is not one of your making, but the choice cannot be avoided. Rational thinking demands to minimize the harm, if harm cannot be avoided. It is obviously better for 9 people to survive than to have all 10 to die. If there is a volunteer, then no force is needed, and the problem is solved. If there is no volunteer (possible!) then a draw of luck is preferred.
As to the likelyhood of such situations. There was a disaster in the Andes, where a plane went down, and people HAD to resort to cannibalism in order to survive. They did, and no one ever blamed the survivors for their actions, even though there is a very strong prohibition against cannibalism.