Although the event happened way back in April 2017, few of us can forget the images of that 69-year-old Kentucky doctor--David Dao--who was knocked out then dragged off a United Airlines plane when he refused to give up his seat on the overbooked flight from Chicago O'Hare to Louisville, Kentucky. In one remarkable act of poor customer service, United Airlines earned a ton of bad press that lasted for months.

While it's impossible to calculate the cost of all that bad press for United, reports say that the airline reached a confidential settlement with Dao to the tune of $140 million for the injuries he suffered, including a broken nose, a concussion, and broken teeth.

In a recent interview on The David Rubenstein Show, as reported by Bloomberg, United Airlines CEO Oscar Munoz had some surprising things say about the incident.

"It's one of the dark moments...usually the question is, 'Are you glad that's getting behind you...?' and I always say, 'No, I'm happy to be reminded of it every day, and so is our company, because it's important to know how quickly things can go sideways on us."

Munoz went on to point out that, subsequent to the Dao incident, the company created a new set of prioritized Core4 principles, which raise customer service to a higher level:

1. Safety

2. Caring

3. Dependable

4. Efficient

So, while United is still dealing with the fallout over David Dao and emotional support animals, the company is clearly trying its best to raise its customer service game. Time will tell if CEO Munoz and his team will be able to create lasting change in the world's third-largest airline.