Think of Shakespeare.

How did he know Dogberry and Pistol, Bardolph and Doll Tearsheet?
He must have gone about with them.

You don't go about with public school boys of your own class, for you know them; you have nothing to learn from them: they can teach you nothing.

But the stable boy and servant you cannot sketch in your plays without knowing him, and you can't know him without getting on his level, and letting him call you 'Oscar' and calling him 'Charlie.' If you rub this in, the judge will see that he is face to face with the artist in you and will admit at least that your explanation is plausible.

He will hesitate to condemn you, and once he hesitates you'll win.
"You fought badly because you did not show your own nature sufficiently; you did not use your brains in the witness box and alas--" I did not continue; the truth was I was filled with fear; for I suddenly realised that he had shown more courage and self-possession in the Queensberry trial than in the trial before Mr.Justice Charles when so much more was at stake; and I felt that in the next trial he would be more depressed still, and less inclined to take the initiative than ever.