Had a check airman at our big airline in USA ask what I would do if I took off from US and found non of the lavs were working on a trip to Europe. I said I would return and land. He said would you declare an emergency. I said no. He said if you land overweight you have to declare an emergency. I said OK. I didn't say I only said that to pass my check ride not that I would really do it. My friend declared an emegency because of this same thinking and got to watch all the fire trucks greet him when he landed overweight on a 13.000 ft runway. Do what ever you want. I try not to get paranoid over the simple things. Some day it might bite you but using logic worked for me. Now I am retired so it doesn't matter.