Cell Phones and Youtube

So yesterday there was a verbal confrontation between these two guys on MUNI and one of them was obviously drunk (go figure). The two guys were shouting at each other and sending each other death threats and such. It escalated and when the bus stopped at their stop, the drunk guy, who was standing right next to my sister and I, bumrushed people through the aisle, --including a couple of kids-- while smacking a few people with his beer bottle and brown paper bag along the way allthewhile trying to catch up with the guy he was arguing with. They tumbled off the bus and fell to the ground, and the seemingly sober man pulled out his "weapon" and apparently hit the other guy with it, which caused him to bleed. Now, the people off the bus who witnessed this altercation instinctively pulled out their cellphones, however, they didn't do what one would assume should be the correct response. They instead recorded the fight and let the two guys beat each other to death, or what seemed like death. I thought that was strange. Also, my actions weren't just either, I just sat and let adrenaline pump through me as I watched, and not once thought about pulling out my phone to call 911. Eventually, the bus driver drove us away and called the police when we were about a block away. My sister and I talked about this, and she brought up an interesting point: why didn't anyone call the police once they saw what was happening? I know, that at least a few people did dial them up but when I saw so many phones pointed at the two men it made me wonder even more. Is this where our society is headed? Are we approaching the times where an emergency will be responded to by a bunch of commenters on a socializing website? Or was it the fact that humans always need a leader or someone to depend on that some people did not call 911? What I wrote is all a bunch of jumbled and perfectly justifiable.mess, I know. And I also know that I might be wrong about some things. But I wonder about these things.  What are your thoughts? Please be respectful.