In Captain America: Civil War, Black Widow says "You could at least recognise me" while fighting a 'hypnotised' Bucky. Most people suggest that it's simply a reference to her past encounters with him from The Winter Soldier and prior to that film, and possibly there relationship from the comics.
Natasha Romanoff: I know who killed Fury. Most of the intelligence community doesn't believe he exists. The ones that do call him the Winter Soldier. He's credited over two dozen assassinations in the last 50 years.
Steve Rogers: So he's a ghost story.
Natasha Romanoff: Five years ago I was escorting a nuclear engineer out of Iran, somebody shot at my tires near Odessa. We lost control, went straight over a cliff, I pulled us out, but the Winter Soldier was there. I was covering my engineer, so he shot him straight through me. -IMDb
Black Widow was a former KGB operative before joining SHIELD.
"At a young age, Romanoff was recruited by the KGB." -Marvel Cinematic Universe Wiki
Bucky Barnes was part of the Winter Soldier Program which was a Soviet/Hydra program. And apparently was given his name because of his work with the KGB.
"The Winter Soldier Program was a top secret Soviet project started by Arnim Zola that involved brainwashing American hero James Buchanan Barnes and turning him into a deadly assassin for HYDRA using a serum similar to the Super Soldier Serum." -Marvel Cinematic Universe Wiki
"Receiving vast training from HYDRA, Barnes became a formidable fighter and an even more ruthless killer. His experiences with the KGB would earn him the name of the "Winter Soldier." -Marvel Cinematic Universe Wiki
My question(s), is it possible that Black Widow saying "You could at least recognise me" had much more significance than just referencing Captain America: The Winter Soldier and her experience in Iran?
I understand that it may be a stretch and she hasn't really given any other indication that this may be the case. Being that she is apparently one of the worlds top spies, like Fury, she holds her cards close to her chest. Could they have crossed paths before while she was still with the KGB, but she is yet to explain/admit this?
I also understand that similar questions have been asked on here before. However these questions and the answers provided do not take into consideration that the comment was referring to something that is yet to be properly explained. The answers dismiss the comment as simply being sarcastic and/or referencing Captain America: The Winter Soldier. Whereas I'd like input on whether or not the comment was or could be much more significant than this.