I think you need to read first on the statement of OP, correct stealing is illegal but base on the OP statement he was generated bitcoin address with the balance accidentally that is why i think that is not form of stealing he only a lucky person on that time
Indeed, and my first question is..Is it possible? But since the thread starter says it...I consider it also a lucky day for him. First, the owner is innocent and the address was generated for him. He did not do anything to steal, its not on his mind or not premeditated.
actually i'm a little doubts with the statement of op because I think it is impossible to get the balance of the address he made even though it obviously is not the act of theft.