You want accuracy, but not representation. If you know how to make the figuration, it doesn't work. Anything you can make, you make by accident. In painting, you have to know what you do, not how, when you do it.
Why do so many people chose to spend their whole life destroying paths they didn't even want to follow, instead of following the one path that would lead them somewhere.
The prosecution wants to make sure the process by which the evidence was obtained is not truthfully presented, because, as often as not, that process will raise questions.