Pro tip #6: get over ourselves, take the high road and let the babies fish the way they want and just keep moving up stream to a better, more productive hole.
If there is more than one person fishing a hole, chances are it has been spooked so badly those fish are not going to budge for anything. Best to keep hiking.
If somebody barges in on your hole without saying hi, try and chat them up as much as you can. Chances are you'll probably end up making a friend. Best way to roll and sometimes you learn something useful from the other person. Worst case, a person crashes your hole and they really are a dbag, they will get annoyed at you talking to them and leave after a couple drifts. Problem solved.
In other circumstances, just move. I mean, how many fish can you catch out of one hole, even if it is stacked? Give somebody else a turn. If the other person is being a dbag, nothing sends a message more than walking away like he stinks.
Whatever you do on that river, keep it classy. You don't have to be nice or a role model, just don't be a jerk. People will respect you for it and be willing to give you an extra inch. Just don't take the mile. It goes for everything else in life.