I would say that calling Dr Dao a trespasser is stretching either the term or the truth. The actions of police vis-a-vis passengers are not dictated by just general laws (like trespassing) that govern everything. They a dictated by industry specific regulations & policies about what is & isn't OK for the passenger and/or airline to do. These regulations are implicitly and explicitly written around the business models of the airlines, in collaboration with them.
We could probably litigate the details of this incident incident at length along the lines you suggest, but I don't think you can ever find the smoking gun of corporatism in individual details. Corporatism is about the systemic.
Corporatism exists where corporate and state power are merged.
In this case, a tell tale sign is how confused commenters on this thread (and journalists) get about about what is airline policy and what is industry regulation.
For example, it turns out (I think) that the regulator sets maximum compensation for involuntary deboarding while airlines set their own max for voluntary deboarding. I imagine that most passengers, crew & airport police have as much trouble demarcating these as journalists do.
When the regulator sits down to try and prevent future incidents like this (maybe right now), they'll ask to see United's policies on involuntary deboarding. They might get United to revise the lottery policy. They might issue new guidelines. They might standardise deboarding policies banning lotteries. Or United might, it's hard to tell.
I think an argument can be made against treating this as trespass. There is a (rather long) contract between the passenger and the airline. There are many reasons they list on the contract why they can deny transport, but wanting that seat for their own use is not one of the reasons. If a landlord rents you an apartment, there are reasons they can have the police evict you, but wanting to kick you out because the landlord wants to use the apartment for the use of his family is not one of them.
I am sorry to say the client is not trespassing since he already paid, he got this seat number and is already seated in the plane. The trespassers were the 4 employers that the crew has decided to kick the 4 others clients. That is called favoritism.
If you frame it that way, then it does sound outrageous. This:
> They were informed that corporate policy required them to drag a passenger of the plane. They said OK, I guess that's our job.
makes it sound like the police think it is their job to enforce corporate policy.
But is that accurate? The airline owns the plane. They have the legal right to decided who is and who is not allowed on the plane. They allowed that particular passenger onto the plane, and then later they revoked that permission. When he refuses to leave at that point, doesn't he become a trespasser?
From the police point of view how is this any different from any other situation where someone is on private property without permission and refuses to leave? In most countries, I believe, removing trespassers is one of the normal functions of the police. Generally, in civilized countries, we want the police to do that rather than having the owner try to force the trespasser out themselves.