We had one like that last year, just smiled and waited as the guy was getting help from his kids and had some hose issues... it took more time than I wished, but I could have left 10 minutes sooner and he would have been behind me waiting on me. My wife makes sure I have gloves available and when finished some hand sanitizer and paper towels... goes reasonably fast.
We try and allow extra time when we have to dump, not only in case someone is in front of us that we wait on, but also for unexpected issues during our own dumping.. Sometimes while watching someone else dump, I learn something that makes my process easier and quicker.