Obviously, as this gets finer and finer, and eventually it becomes trivial. You'll have to decide for yourself where that occurs.
As an analogy, most people would say that going 100 miles over the speed limit in a residential zone is dangerous and immoral. So is going 50 mph over. Well, going 10 mph *is* more dangerous, just not a lot. Maybe it's a little immoral to raise the danger to adults and children in the neighborhood just so you can get somewhere a little faster. Then what about 5 mph? 2 mph? 1 mph?
We're adults here. We can use our judgement. (But I reserve the right to criticize the guy who's fine with going 25mph over the speed limit when they're kids about.)