I'm not an expert in anything but I have a hunch. Taxidermists usually do alot of deer and that is their bread and butter. They know their subject. When a cat is brought in, they don't really know the anatomy and natural expressions of them. Usually don't have much experience with them, and the mount is possibly their first attempt. They are basically a beginner and the work shows. I think that careful study of reference materials and time invested would pay off. Trouble is, they have a ton of deer in the freezer and do not want to spend excess hours on the cat. It is a shame really...why waste a nice trophy, many hours and someone else's money
if you are not going to do it right. Personally, I would do whatever it takes to make it decent, or turn it down to begin with.