Welcome to OCDO - good people and good information abounds here.
Regarding your incident - you do realize, do you not, that the police office made some very serious mistakes?
At the very least your are due an apology and the officer needs retraining. There is enough wrong here to warrant further action, that of course being up to you. I would advise posting no more on that event until you have talked to a good gun rights civil attorney.
I can guarantee that putting me on the pavement and a knee to my back for violating no laws is not getting anyone a free pass.