Trespass, interfering with a flight crew, failure to obey a lawful order.
Nobody read Dao his rights. No one threatened him with arrest. Munoz, CEO of United, said Dao was not in any way at fault.
He was not trespassing. He paid for the seat he was sitting in. He was allowed to board the airplane and was not in violation of UAL's Contract of Carriage.
He did not interfere with the flight crew. He merely stated he was not going to deplane because the flight crew had no rights under the CoC to remove him from the flight. (See: RULE 21 REFUSAL OF TRANSPORT)
The section on RULE 25 DENIED BOARDING COMPENSATION does not apply because that section deals with denying boarding to a passenger due to oversold conditions.
A) the flight was not oversold.
B) He was allowed to board and was already in his seat.
...failure to obey a lawful order.
What lawful order was given?
You might be interested in a couple of legal opinions on the matter:
United Airlines Cites Wrong Rule For Illegally De-Boarding Passenger
This article deals with the concept of Dao 'tresspassing' on the airplane.
See: United Airlines' Own Contract Denied it any Right to Remove Passenger