Sin is not defined as such by any level of hurt caused to a human being. Sin is, in fact, "missing the mark"; the word has it's roots in the target-shooting of an archer - sin is, in effect, to miss the bulls-eye. First and foremost sin is any failure to live up to the perfect law of God, including all it's moral statutes. For the Jews, this included the social, moral and ceremonial statutes handed down from God through Moses.
Nowhere is it stated that sin is sin by man's measure; it's sin by God's measure.
Now, that being said, the old testament law was fulfilled in Christ, and he gave a new measure. It was one which was more about the heart than the head, and harder to live up to than simply following a bunch of regulations; it's a "law" of principled obedience:
12 So in everything, do to others what you would have them do to you, for this sums up the Law and the Prophets.
37 Jesus replied: “‘Love the Lord your God with all your heart and with all your soul and with all your mind.’ 38 This is the first and greatest commandment. 39 And the second is like it: ‘Love your neighbor as yourself.’
34 “A new command I give you: Love one another. As I have loved you, so you must love one another.
And this new code is a law of the Spirit:
4 So, my brothers and sisters, you also died to the law through the body of Christ, that you might belong to another, to him who was raised from the dead, in order that we might bear fruit for God. 5 For when we were in the realm of the flesh, the sinful passions aroused by the law were at work in us, so that we bore fruit for death. 6 But now, by dying to what once bound us, we have been released from the law so that we serve in the new way of the Spirit, and not in the old way of the written code.
So the question is: Does X show love, honor and respect for My God, my neighbor and myself? However, living this principle, this new law of love, is a thing in which we grow day by day and we are more conformed to the image of Christ.