It is up you to prove that you were not.
So you're guilty until proven innocent under Australian law, then?
... and you are operating outside of a limit of that chart, then you are breaking the law.
Ok, so which law is that?
The short answer is you can't
Actually, there are ways, involving your experience. For example, you could say, "I took off perfectly safely yesterday, under the exact same conditions". Note that the law doesn't stipulate how you have to assess your takeoff performance.