I am on the 757s often as I fly quite a bit between SFO and BOS. When my upgrades don't come through, I always choose Seat 9A. It gives me a window view, leg room and I don't have to climb over two people if I want to use the lav. The FAs usually are willing to let me store my briefcase behind 6D-F. As soon as the seat belt sign goes off, I bolt out of my seat and grab my bag.

I agree with the sentiments expressed in the other comments -- basically, I think you made a mountain out of a mole hill, especially if only a briefcase was involved.

There was one time when I had a larger carry on item (gym bag) that I put in the bin above me; someone in Row 10 had the nerve to take it out and move it to a bin closer to Rows 12/13 to make room for 2 of his bags. Had the flight not been full, I may have let it go, but at arrival I was not going to fight my way back or ask someone to pass it to me from 3 rows back. So, I calmly got up, retrieved my bag, and switched it with one of his bags. He was on his cell phone gabbing away about his golf game, so I did not interrupt him. When we landed, he had a panicked look on his face -- he was on another phone call so I did not interrupt him - that would have been rude.