RE: what do you do when.......
I agree with BossTom. Besides the tips he gave, the birds on that one property might be shut down for some reason or another and a back up spot is in order.
In your situation 10 point, you were there, setup so the other guy had the opportunity to converse with you and he didn't. I say you did the right thing and you were successful because of it. Like you said, had the other person been respectful and talked with you, you might have teamed up on a double.
<font color=blue>Good Luck and Good Shooting</font id=blue>
<font color=red>Rob</font id=red>