I really hope he is OK. But this is the perfect storm of things to go wrong to send a message of police violence to every (white) American. An old white man, non-violent in broad daylight, 3 meters from any other protestor - may not even be a protestor really, just a curious lookie-loo - with 20 plus armed cops in sight. Gets pushed with a visible and instant traumatic head injury. An audible gasp and stop motion from the crowd. The cop who goes to help gets pushed forward by other cops to arrest another non-violent protestor. The cop is easily identifiable. And it was caught by a true news cameraman, not a cell phone.
And the Police are already admitting no wrongdoing and saying he just tripped.