I happen to agree with the union...Dr. Dao would likely be dead from either multiple tasings, or a GSW. UA's pilots union may be outraged, but their head is clearly up their back passage.
It is the UA pilots union that created this situation, assault and actual bodily harm, from what I have read they are so inflexible, they insist that crew positioning/deadheading must be by scheduled service thus eliminating any other option for all the UA ground staff concerned, they couldn't possibly charter an aircraft or even a limousine to move the crew because UA pilots union had outlawed such an option.
When are these people going to ever learn to stop digging holes for themselves?