After he thought his time filming in New Zealand was long over, Sean Bean was called back by Peter Jackson to film an additional scene for the trilogy. (The rest of the cast were still filming films #2 and #3.) Sean was back after being away for a time from playing Boromir, and I think he was filming again in NZ for a week or so, and he wondered whether he could get back in character again.
More relevant to what has been going on with The Hobbit cast and their goodbyes is Sean talking about how it felt to be back with his friends again, and how he wanted to stay with them longer once filming Osgiliath was over.
Peter Jackson changed his mind it seems, and the scene, one of my favorites from The Two Towers, never made it to the theatrical version, but it did to the Extended Edition. So we may see some scenes in those 13 additional minutes on The Hobbit film #1 Extended Edition that may become our, your, personal favorite. You never know.