And who's to decide if the baseball bat was willfully thrown? The jury! You could still be charged with assault because 1000 people saw your bat hit someone in the face, so its 100% plausible to say you broke the law.
If the law says don't cross the line, and you accidentally cross the line, you broke the law, regardless of willfulness. Its up to a jury to decide if youre guilty
Its not like the police have an "accident detector" they roll up to the scene to determine if a law was broken.