In injury cases like this, quantifiable medical injuries are normally the primary factor in assessing value. Indeed, Dao sustained medical injuries, but the extent of them may not be the kinds that are likely to produce a significant payout.

Broken teeth are certainly painful, but that period of pain could be limited to the time between the injury and when the dentist fixes them. The price of those teeth is also an ascertainable amount. Ten thousand dollars might be a reasonable value of some dental implants, but it's the kind of injury that is largely fixed once the procedure is over. Similarly, a broken nose that heals on its own is painful, but probably not for the rest of one's life.

The real driver in high damage awards in personal injury cases is long-term pain or impairment. For example, herniated discs and torn rotator cuffs are not gruesome, obvious injuries, like broken teeth or noses. Yet, they can lead to long-term treatment and surgeries, permanent disability and a lifetime of pain.

This is also why personal injury cases normally take a few years to resolve. Assessing the extent of certain injuries requires waiting to see how bad they get, and whether they get any better. That's why Dao's case was unconventional, and not really about the injuries. The parties didn't wait to see how Dao's recovery and treatment defined his injuries over time. They settled within weeks. This case was more about United's public relations headache, than Dao's actual headaches.

Yet, Dao didn't have as much leverage as it may have seemed he did. His injuries alone didn't strike fear in United's lawyers—airlines litigate passenger injuries all the time. Instead, United desperately needed Dao to agree to settle to stop the flurry of bad publicity.

But with each passing day, as United suffered the bad press it wanted to avoid, the amount United would pay to avoid that bad press decreased significantly. Had Dao waited a year, the one thing he had to offer—ending the bad PR—would no longer be worth anything to United. Heck, I have to imagine there were lawyers in United's camp that suggested hunkering down, waiting it out and playing hardball until few remembered the incident—as tends to happen with viral videos.

That's why Dao's attorneys did the right thing in settling quickly. It also indicates that United probably paid well north of a million dollars. Why? Because by settling early, Dao takes a risk by giving up the opportunity to build the value of his case the traditional way: a couple years of medical records documenting the nature and extent of his injury and treatment. The settlement amount had to be a number that Dao felt comfortable accepting, even if his injuries take a turn for the worse in the future.

That's good for him, but not an indication of what other plaintiffs might get if they file cases against airlines. Dao's case is one-in-a-million. For the rest of the would-be plaintiffs out there, United will probably see you in court.