what if segfaults only occurred when the errant path was executed in manners not initially designed for? or alternately, if that code path never got touched, wo

what if segfaults only occurred when the errant path was executed in manners not initially designed for? or alternately, if that code path never got touched, would we ever have known about the segfault? should we keep focusing on segfaults or look at the ways that programs are being operated out of scope?