EBarnacle here, Graham
It hasn't done me any harm, therefore it's not so bad.
The theory behind this statement is flawed, based upon the Orthodox and other philosophical rationales. Among various religions, that way lies damnation. Road to Hell, etc. The point of the orthodox rationale is that the strictures are deliberately not easy. If they were, there would be no test of character and the soul would not grow strong. The object is not to get away with variations on the rules, it is to adhere strictly to them despite inconvenience.
Consider that YHWH, the tetragram for God is often translated as "I am who I Am." Similarly the concept behind Orthodox Judaism is "We are who we are." Note the differences in capitalization. If you, as do the Orthodox [or Frum (meaning proper or correct)] Jews believe that Jews are the Chosen People, what does chosen mean? They were chosen because they accepted what was presented as the word of God, with all of its rules and strictures.
Refer again to my previous note. As sin is a sin. Any sin diminishes the soul. Intent is worse than lack of intent but there is still a level of diminishment.