Well, there was no life-threatening emergency. He was not a terrorist. He was not threatening anyone. The people-who-weren't-really-police should have made sure of the situation before getting violent.
The airline manager should have made the situation a LOT clearer before calling for people-who-weren't-really-police.
As LP pointed out, you can't stall with a cop sayin gthat you are talking to your lawyer.
If you don't really know what you're arresting a man for, maybe you should pause if there's a chance he's got a lawyer on the line.
If you don't really have the authority to arrest someone, maybe you should pause.
When i first joined the Navy, one of the conditions of deadly force was 'when so directed by competent authority.'
They decided there's a problem with that, with just blindly following the orders of the senior man in the room. That condition went away.
I'm guessing security people are going to hesitate just a teeny bit in the future, probably to their profit, if there's no clear and present danger.