The guy agreed to get off the plane for the voucher, hotel and so forth. He then left the plane on his own. When he found out that the next flight was tomorrow and not in a couple hours he ran past security without a ticket or permission and boarded the plane and refused to leave after they asked him to multiple times.
Had he not left the first time they would not have handled it like this. They would have continued to up the offer to get people off the plane. Or they would have started pulling people to the side and offering them. The force might have been excessive but what should they have done in this case? He should not have ran past security and re-boarded the plane. This one is on the passenger but the airline will pay the price for this one even though they really did nothing wrong. They rightfully called the police and the actions of the police are outside of their control.
They could have still let him sat down and continue to up the offer.