Only happened once. They could have just not and everything would be fine from that point on, but I can't hold it against them because the inconvenience I afforded them was fully my responsibility.
Stone Vigil. I'm tank. We get a few trash mobs in. My connection cuts (that's what I get for being in the northern part of a country like Wales). First and only connection drop of the day but it takes a handful of minutes before I can begin the log in process again. In less than 5 minutes I was back and without a word I received a kick a few seconds later.
I might have been more merciful but fair play. I've played plenty of other games where the etiquette is to sit down and shut up if it's your connection alone that cut, and rightly so.