Im not sure if inspecting the restroom is a fullproof way to judge the kitchen of a resteraunt. they are aware that people see the restrooms but unfortunately we dont see their kitchen. However, if the restroom is dirty, I probably wouldnt go back there to eat again.
I have to agree with Chels, My desire not to cook far outweighs my desire to not eat out. Ill just stay in denial and enjoy my food prepared by someone else and hope I live to tell about it!