Wolves and Coyotes have a healthy fear of humans and in order for them to attack they are either sick or extremely desperate, they typically follow easy prey like deer and deer typically get spooked easily by humans so they tend to stay away from us, meaning wolves and coyotes tend to be away from us too.
I had one occasion a few years back where a pack of coyotes circled me an a buddy of mine, the scary thing was it was in the middle of the woods pitch black, we lit a bonfire and they always stayed just out of lights reach, we could hear them yipping and walking through the woods circling around us but we couldn't see them. So we did what any good Canadian would do, we broke out the beer and had a few by the bonfire ..
My guess is the ATV's got their attention and they were curious to see what these weird looking creatures on two legs were doing. the knew exactly where the lights edge was and would never cross over into the light, they are very smart and very efficient hunters, if they wanted to come after us they would have.
They are so good / smart at hunting they will befriend dogs to get them back to the pack just to kill them. I've actually seen a single coyote go up to a dog, play with it and try to lead it into the woods.