I met one. Most of my encounters have been very professional and polite, but the first DOW (at the time) encounter I had in Colorado was one that almost ended with me dead.
In college, a couple of friends and I decided to head out to a state wildlife area for a rabbit and squirrel hunt. I read and reread the rule book, and knew for certain that both were in season. I read the requirements for licenses and such, and obtained what I needed. The three of us went out and hunted for a few hours, each getting a few critters, but well below our limits. As we walked to the parking lot, we see two wardens, one old, one young. The young one draws his pistol at about 50 yards and points it at me. He told me to "drop the weapon", my single shot, bolt action .22 that was slung over my shoulder. My friends dropped their .20 gauge single shot and 10-22 onto the ground. I kept my hands in front of me and visible and explained to him that my grandfather had given me that rifle, I was no threat to him, and I would gladly lean it up against the tree next to me. He yelled for me to drop the gun or he would shoot. I yelled back. I told him that he would have to live with killing me if he chose to murder me for taking care of a family heirloom. I leaned the rifle against the tree when the older warden put a hand on the younger guy's shoulder and whispered something to him.
We were separated, our licenses checked, our rabbits and squirrels checked, and then berated for about 20 minutes about how stupid we were for not wearing orange. I explained to him that the regulations did not require it, and as broke college kids, we didn't have any with us at school. Eventually we were let go with a warning that we were stupid.
I don't know what set him off, and can only assume he was fresh out of an academy that convinced him everyone wanted to kill him, and the older warden was his FTO.