What is difference between right and wrong?

Lot of times when I write here, I feel that we are trying to look at instances in our life or issues in life - in general for which we don’t have a specific textbook answer, for which there is no set rules, for example, recent post by Restlesstraveller. What she is trying to understand is something very subtle, something which can not be discerned by an ordinary eye. I am thinking about ethicality.

Let me give you a famous example usually taught in ethics class....known as Heinz’s Dilemma. Heinz’s wife is ill, he does not have enough money to buy medicines, and his pharmacist refuses to give them on credit, even though Heinz has been a good citizen. Heinz ends up stealing drugs from the pharmacist. Who is wrong?
(a) Heinz – because he stole drugs which is unethical...but he saved his wife’s life. (b) or Pharmacist – because he did not have sympathy for Heinz’s wife...but he was adhering to his business goal, he is market to make money and that’s what precisely he did. So there are no set answers to certain questions in life.

That leads me something that I did today. I will not be able to explain the exact details but from ethical perspective (again ethics being rules and principles commonly accepted by the society, to remove any confusion), it may be deemed as wrong. But at the same time, I did it at the wish of somebody else. I had no motive of incurring it myself. So who is at the fault, the person being an ethical person had opportunity to judge his own act but who requested me that I do the deed....or me, because me being an ethical person had prerogative to judge his motivation! I can contend that something that executed today may be used to save my skin down the line if need be.

Again, the act had no impact on whomsoever, and if at all, it will be me.

I am not sure if this catharsis is a defense for my actions or was that whole thing an instance by itself which can not be judged from set perspectives.

PS: My office mate had a book that he purchased in India, it’s a quite famous book but I could not read past first 3 pages, name of book is “48 Laws of Power”, and to sum up in line, it basically details Machiavellian techniques in 48 small chapters that you can use and apply in daily life. Well, it is one of those things that I don’t want to recommend but would like to recommend to make aware my friends about how many ugly things can exist in this world.