As long as it's within voice command I think your obeying the law.... just make sure your dog doesn't smell it's farts too close to my big as mastiff on a leash... He's very well trained but loves to play.... I'm sensing you and your dog are fragile.
People like you think rules do not apply to you. I bet your dog is precious and well behaved. The problem is some people may not appreciate you not leashing him/her because they don't know all the great things about your best friend. I just think maybe you should be leashing him/her for the public park walks so he/she will not run into some of the crazies that are in some of parks these days. Keep your dog safe,respect the rules of being a responsible pet owner.