I think the more serious error here is the error you display: "people are asked/told to get off planes every day." That may be true, and maybe in most cases results in only a grumpy exit, but this situation seems to have exposed that it is not a legal requirement, and that people's generally co-operative nature has led to routine infringement of consumer's rights. Dr. Dao was not clearly obligated to exit the plane, and the justification for the "police"'s removal of him depends upon the now-questionable claim that they were okay to do so.
Certainly we are putting too much of a premium on peacefully resolving situations at the expense of fair treatment. Your story should start with whether Dr. Dao was, in fact, obligated to incur thousands of dollars in losses by being "randomly" selected to miss a work day on which an entire medical office depends, in exchange for 800 units of United scrip.