I don't believe race had a thing to do with it. If that had been anyone (anyone the cop felt confident in attacking) he'd have acted the same way.
As long as it was someone he could manhandle and feel like "the boss" it would have been the same.
I also do not believe the myth that police are racist -- i think they are equal opportunity - im a conservative white early 50's male and i wholeheartedly believe that if i was popping off and pushing and shoving - i would get "told twice" - or tazed - etc,
That said , i was served with papers several months ago by several members of our local LEO -- when asked to exit my vehicle , i stood - legs spread, hands clasped in front of me and kept most of my responses to Yes, No and Thank You - at no time did i ever feel threatened under the circumstances
However regarding the elderly, -- i think additional training should be in order on how to deal with older folks who are cranky or out of it - we've all got mean older relatives (maybe some of them post here on OSA ?) - but definitely dont want to see them injured