Why do you jump to murder, stealing a pack of chewing gum is exactly the same in principle as it is illegal. Your flaw is trying to make the distinction that increasing the scale of the crime makes it any different to my principle. And thus i render you to be overly emotional and so you loose any argument.
OK then. Stealing a packet of chewing gum is still illegal, regardless of whether you get caught, and indeed regardless of whether you are observed.