This is a flaw with (ETA: simpler versions of) consequentialism: no one can accurately predict the long range consequences of their actions. But it is unreasonable to hold someone culpable, to blame them, for what they cannot predict. So the consequentialist notion of good and bad actions doesn't translate directly into what we want from a pratical moral theory, guidance as to apportion blame and praise. This line of thinking can lead to a kind of fusion of deontology and consequentialism: we praise someone for following the rules ("as a rule, try to save a life where you can") even if the consequences were unwelcome ("The person you saved was a mass murderer");