You did pretty much what I do routinely on Wildcat Canyon Road: when I see a car or a bike coming down and there is a car approaching from my rear, I put my left arm straight out, palm toward the car approaching from my rear, and move a bit more into the lane. I also, if a driver has been a good boy or girl and has slowed to my )ridiculously slow) climbing speed because they can't see around a corner, if I can see it's clear before they can, I will wave them through (I only do that if I am 100% certain it is safe for the car to pass) and then wave at them as they go by. I get a fair number of waves back. I believe in rewarding the behavior I want to see happen.
As for the Ranger, he seemed a bit ignorant about the applicable law. But at least he was willing to listen and didn't get all defensive and macho about it - it seems like he actually listened. Whether it sunk in or not is another question: I hope so. But at least he did not seem like a cop whose reaction is a reflexive "you stupid @$$ cyclist are wrong period and I don't care what the law says."
Scott, you handled it pretty well. You sounded a bit irritated to my ear, but certainly not out of line. You explained yourself patiently and well, you found common ground with him (safety) and you gave him plenty of conversational room to back off without losing face. Nicely done.
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"I'm in shape -- round is a shape." Andy Rooney