I think you’d probably have decent odds in court if they did unjustly lay hands on you and you defended yourself, at least if you’re white. You’d need to prove you had valid reasons for defending yourself, and that you didn’t use more than the least amount needed, but they’d also need to prove they did the same. I imagine the courts would have a hard time accepting that tackling and dragging an elderly person is a reasonable use of force, but crazier things have happened

Edit: obligatory IANAL