Got stopped by a California SO for something similar. Three way stop intersection with Deputy sitting on the roadside in plain view.
Truck in front of me stops halfway over the stop bar on the road, I stop behind him and just behind the stop bar. Truck pauses for another vehicle to clear intersection then turns right. I do not move forward (no need) and there is no opposing traffic. I turn left and drive on.
He stops me, wants my license. I tell him I have to get it from my wallet in the door panel next to my off-duty weapon. He says to do it and never caught on to the "weapon" statement. (Weapon inside vehicle is a no-no in California and I know it) I give him the license, he asked if I know why I stopped you. I replied "No idea."
He claims I didn't stop for the stop sign. I tell him I certainly did stop, and in the correct position as well. He leaves to run my license.
He comes back, hands me my license (never asked for 28 information) and tells me to "slow it down for him". I reply "I wasn't speeding." Roll up my window and drive off with him standing on the roadside. Wife and I look at each other like WTF was that? (She's a cop as well)