I'd not wholly agree with Dave there - it's too easy to come up with situations where some act intended to harm someone might in the event turn out to benefit them. A thug puts someone in hospital, where they meet the nurse who turns out to be the live of their life; someone makes a rival lose their job by some false accusation, and he or she promptly gets a much better job. In neither of those cases would the happy outcome serve to justify the malevolent action. Or it could be the other way round - you help someone go on holiday, and some totally unexpected accident arises, and they get killed.

What matters is your intention, together with the consequences whch can be reasonably be anticipated.