Yes and no. Yes, if the toilet is on land and no if it is mid air. This funny situation happened in Norway when an airplane flying 84 plumbers from a local plumbing company had to make an emergency landing because of some issues with the rest rooms. Imagine the condition that the plane had 84 experienced plumbers onboard and no one could initiate to fix one restroom.
Image source : http://bit.ly/2EANz7P
The Munich bound flight had to take an U turn and return from where it had started to fix it's toilet. The plumbers onboard were heard making jokes about how funny the situation was. It took around 2 hours for the technicians to fix the snag and the flight took off and reached it's destination.
So, always remember, no matter how expert you are at your job, the situation should be right to work and fix things. 😂