I think the most common altercations you will hear happens sometimes between spouses as they back into their site. We laugh when when it happens to us, but others don't.
We camp about 8-10 weekends plus vacation each year and have never had an altercation with anyone. Once some people walked through our daughter's site about 3 inches from their TT, startled their dog who was inside, and she barked really loud, not snarled, barked. They were offended, too bad, they should not have been 3 inches from her TT.