The flight was a very light flight (read plenty of open seats).
But two items:
First I board with the medallions and usually do not pay attention to how many people are in the waiting are (SLC is always packed) so at the time I did not know how many people were coming.
Second its all about approach...If he would have been polite about it I would have given him the seat. It's that first impression of rudeness that makes me set in my ways and once there I would not have backed down for any reason..unless a FA got involved and found me in the wrong.

I've given my seat up plenty of times and do so gladly if the person is polite...that's all I ask.
annerj