Yeah, there's sometimes a hefty incentive for doing so, obviously $800 wasn't enough in this case but it's going to cost far more now.
It just made more sense to keep upping that 800 until someone volunteered. I'm sure in 99% of case they can have someone removed safely, sadly the other 1% where the security you've called in are overly aggressive have then caused a major news storm painting your company in bad light.
Be certain that UA are working with their legal team writing up non disclosure and essentially gagging orders for him to sign in return for some decent Wonga. As for the three thugs, we have to wait and see now as UA are dominating the story.