I believe that there is a message to do with the revealing of their face.
It is easy to kill a masked human because their mask makes them seem..different(?) where as many people refuse to accept that they are killing people, real people.
It may be that (I'M GUESSING HERE) that society is killing people, turning people against others without anyone realizing.Gerard's reaction was to show that he realised that his enemies were actually no different than he was.
