Don't agree with cheaters, but DO NOT assume that everyone who does go to the toilet during an exam is cheating. Nerves make people need the loo and having drunk lots of tea or coffee before the exam will get to them half-way through.
And being able to hold your bladder for 2-3 hours is not a requirement to be a pilot. If you have sectors that long, you'll be up and about stretching your legs and taking physiological breaks, what with the amount of water you should be drinking on a flight that long!