The point is that sometimes even people you believe are the consummate "good guy" do something stupid and shock you. And often someone perceived by society as a "bad guy" does something truly heroic. The media, and we too I suppose, love to label people. In the US, this is so obvious in the whole debate over guns. "Ensure the good guys all have guns and take guns away from the bad guys." But good guys can run riot and massacre others, and bad guys may stop a tragedy from happening. The potential is in all of us, at every moment, to be good or bad.
On the point of what people do in private, I once managed a project where about 12 members of my team had to work on site. At the end of the assignment, I got to pay all the hotel bills. Mistakenly, the hotel printed the names of movies that each person watched - and I was shocked. Also, at a conference once in Europe, I accompanied a powerful CEO and major personality in the industry and again paid all his bills. Once again, I was shocked by some of the things I had to pay for. You just wouldn't believe it - obviously done in what he thought was the privacy of his own room.