Law Evolution Science and Junk Science has an interesting post on the fallacy of the appeal to inappropriate authority.
In summary, an appeal to authority is a valid method of argument and of making decisions. It recognizes the obvious fact that we cannot all be experts in everything. It would be a mistake to have your neurosurgeon change the brakes on your car and your car mechanic to operate on your brain tumor. If you see a neurosurgeon for your brain tumors and a car mechanic for your disc brake adjustments and you don’t know much about either, you are essentially betting your life on an appeal to authority. We all reasonably do that every day.
Analyzing Intelligent Design under the appeal to authority fallacy immediately presents several problems.