As if he read all laws of his own country that apply to him. Raise your hand if you actually read and comprehend all laws that apply to you. I'm willing to bet there's not a single person on this planet who really reads and comprehends all laws completely.
Usually you just go with common sense and reading a blog post or two when it seems relevant: that usually makes compliant and in the worst case it will get you a warning from the regulator (they give warnings for unintentional first-time violations, so they'll tell you if you're doing wrong and it bothers them enough (usually you're too small anyway), and you get a chance to improve).
