"the company would no longer use law enforcement officers to remove passengers from overbooked flights." What? Does this mean that the company currently routinely uses law enforcement to deal with overbooking!?
In any case,  this was not an 'overbooking' situation. The passengers had all been boarded and then a few were 'randomly' picked for ejection - (Wonder just  how this 'random' selection was made). One quietly refused because he was a doctor. - The airline should have at that point looked into offering others on the flight further incentives to volunteer their seats or using their 'random' system to choose another who might be more compliant or - having bounced three paying passengers to make room at the very last minute for their own staff find another solution. Surely a huge airline like UA  has an on call system so that if one person is sick etc.-  another can be called in. Instead, it ordered an assault on a 69 year old. Thankfully there was a plane full of witnesses.