Um, I thought consequentialism was about evaluating the goodness of a course of action based on its probable consequences. If all it amounts to is hindsight then it's not much use for making ethical decisions about future actions. But I think that would be a straw man.

If you apply that crazy approach to consequentialism then I should be allowed to stand on a roof heaving bricks out into the street, and I'm not doing anything wrong unless and until one of them actually hits somebody.