I loved this.
I also got the feeling, while watching this, that some of the people's expressions were annoyance that they had to sit and listen (the whole willful ignorance thing) and not so much that their eyes were being opened. Do we know what the audience was told as far as what the subject of the talk was going to be about? Marketing strategies...or did they know, going in, that it would be about factory farming? I might have missed that.