Doubtful is a probabilistic or conceptual matter.

The Shach brings in the rules of spikot the well-known rule that a doubt about spikah that does not turn over is not considered a doubt about spikah, and he takes the example of an animal that was slaughtered and a bone that was not covered with meat was found (which is a sign of predation), and the doubt is whether this happened before slaughter or after slaughter, and if the animal is slaughtered, lest it go outside, and the Shach writes about this that it is impossible to start the doubt from the second doubt about whether it went outside or not, because if the animal went outside, then it is necessarily assumed that it is after slaughter, because before slaughter I have no nefkm whether it went outside or not.
My question is, is it because conceptually when I say that it came out, I must be speaking after slaughtering, that there is also more reason to assume, probabilistically, that it is a trap, or are the rules of doubt not probabilistic but conceptual?