Basically.....
If the lines in your photograph are not parallel and there are no EXACTLY perpendicular faces then the photomatch cannot be accurate.
I have never modeled anything FROM a photomatch in 'sketch over' mode, rather I have model something first then matched it to the photo, not the other way round.
The higher the resolution of your photo....the more accurate you can match the perspective as the lines are clearer and more defined.
How accurate this method is compared to others-I do not know, but it works for me.
I'm not sure that SU models could be seen as evidence (if thats what u need it for), it could be regarded as conjecture I think. You would need an expert witness I'm guessing.