As noted in the article, allegedly this passenger already had a confrontation with airline personnel at McCarren. Flight personnel may have been alerted to this passenger before take off. The blanket incident just exacerbated the situation.

"At Las Vegas’ McCarren International Airport, Enriques said he saw Hawaiian Airlines personnel speaking to the passenger.
The man told Enriques, “they’re not treating me right. I’m going to call the president,” Enriques said."