What if your foot had tripped him? Kinda unnecessary, not to mention presumptuous, for you to appoint yourself bathroom monitor isn't it?
I've also always figured you can downgrade in bathrooms if needed, the whole point is to keep people from crowding the premium cabins IMO.
On long flights sometimes a walk can be nice to stretch and if you have to go walk might as well take care of any other business that needs taking care of.