This was my first time doing the exam in London, all my previous attempts were in Hong Kong. When nature calls during the exams in Hong Kong, I would raise my hand, one proctor would keep my stuff and another male proctor would escort me to the toilets. They would stand outside the toilets and wait till I finish.
But in London, there was no male proctors in my section, again I had to raise my hand in middle of the exam since I had a large cup of coffee in the morning. One proctor took my stuff and pointed me towards the toilets. When I get there, I saw a male proctor sitting by the toilet door collecting the exam tickets which were returned after the candidate had used the toilets.
I really felt for this guy coz those toilets stink so badly and he must have a very strong emotional quotient to bear the smell for 6 hours.
I had to use the facilities during the exam in Geneva last year and the guy was inside the toilets, but then we were in a 5 star hotel so there was no smell.
I took levels 1 & 2 in London (2011 and 2012) and was surprised at the lack of security in the bathroom. The bathroom was in the back or the room, down a set of stairs, and there was nobody checking tickets or anything. There were lots of stalls and it was very private. It would have been easy to engage in questionable activities if one were so inclined.