From what I see, you've argued that UAL breached the contract of carriage. Okay, so they lose. What is the remedy and what are the damages? See too, Rule 28.
Any breach of contract $$ will be small if any at all...it’s the “pain & suffering”/”loss of income”, etc., etc. that could go big. If he gets a jury trial date, look for United to settle for a large sum. He has engaged a big Chicago firm to represent him.
http://www.airlineratings.com/news/1159/united-issues-second-apology-as-doctor-engages-lawyers
“What is the remedy and what are the damages?”
We can leave that to the plethora of lawyers who will get in the act. At a minimum, they will likely fight to extend the government regulation from Ralph Nader’s lawsuit that instigated the COC requirements to specifically cover types of “overbooking” and remedies if, big if, the airlines obtain a right to throw people off the plane to seat their own employees. Damages for the Dr. and others they likely will include in a class action may include value for their lost time and any other things creative lawyers will come up with.
While United will try to limit responsibility based on Rule 28, not sure if they will be successful. Judges are passengers, just as they are viewers of videotape and users of Blackberries - which appeared to sway their legal conclusions for the consumers in those cases.