There are all sorts of cases where we ignore intention, or at least don’t see good intention as fully exculpatory—and we are right to do so. By thinking hard about what goes into a moral judgment, we will find ourselves in a better position to debate the merits of any particular case.
There are two main considerations that we take into account when something has done wrong—the intent of the actor and the outcome of the action. To take the sort of example used in psychological research, Mrs. Smith thinks your child is allergic to peanuts, makes him a peanut butter and jelly sandwich with homicidal intent, and gleefully watches him die. This is murder. But what if she’s mistaken and your child has no such allergy? She watches with surprise as he says thank you and runs off to play. This is bad intent without a bad outcome. It’s awful but not as awful as murder.
Now imagine a third scenario in which Mrs. Smith is unaware of the allergy and kills your child by mistake. Here we have a bad outcome without bad intent. But she would presumably be racked with guilt—and should be—and might still be charged with a criminal offense. To take a milder case, if you spill your coffee on my laptop, it matters a lot to me whether you did it on purpose. But even if it was a totally unavoidable accident, you should apologize and perhaps offer to help pay for the repair. Outcomes matter even in the absence of intentions.