Frankly, this could have happened to any airline. I'm stunned that airlines haven't figured out by now that passengers are now armed with cell phones & cameras & can document their baggage handlers acting like American Tourister gorillas on the tarmac, as well as any other mishap/misbehavior by uniformed employees. I can easily see them now telling their employees not to act up where they can be seen by the passengers.
And you know passengers will now be singing this song whenever there's a screw-up on United. WTG, United PR!!