There are a lot of things that you can do on purpose to good effective that are disastrous if done accidentally. It's that mindfulness thing. Almost any rule (whether a law or common sense) can be broken advantageously. Most of the time, breaking rules have negative effects. Often for others, but for us as well.
Self-defense, for example, is an affirmative defense: "Yes, your honor, I committed an act that satisfies all of the elements of the crime (assault, aggravated assault...