I personally strive to build my models to best of my ability and we all know how much time, work and effort can go into them. I would not trust a judge to handle my models. I do not personally care if he is a modeler himself because that doesn't say anything about his skill level or how I would like my models to be handled. I'm the same way with my real car. I pretty much do all of my own maintenance. I will not go to any jiffy lube or most mechanics.
I've never entered a competition and I would not enter at the expense of ruining a model.The only person you have to prove to anything to is yourself. However if I do enter one I plan to take pictures in the assembly process and detailed interior photos. So perhaps it will not be necessary for the model to be touched.