Not just this but Brendt was constantly smug and showing signs of joy and constantly smiling when he was showing he was on to Bale. To me this just completely made no sense. A guy who is hell bent on proving bale has emotion is constantly showing emotion him self by being a smug git all the way through the film.
"It's game over man, it's game over!!!"

It's simple: the ruling elite don't follow the rules that they enforce upon the common man.
"It seems we are not all in agreement."
"I disagree!"

The writing was a bit off in the whole movie. Almost all characters showed some emotion at some point. Then again a lot of them were shown to be off the dose so the big con may have been that nobody was actually taking it. Everyone was feeling.

I assumed DuPont was a hypocrite and deprived the populace of emotions in order to make them easier to control.

DuPont felt. He tells Preston right before he gets killed.