teatotally:

Saw Ant-Man yesterday, despite…well, everything I feel about it. I literally gasped and clutched my BFF’s arm when I saw the last piece of music in the credits, though–”50 Year Old Ghost Story,” composed by Henry Jackman. I couldn’t really hear the music in the cam rip of the Steve and Bucky and Sam tag, but definitely could in the theatre, and that credit convinces me that the scene is from Cap3 and not a fake-out filmed just for Ant-Man.  

FYI all the news articles talked about the director seeing the dailies of cap3 when he was editing Antman. He thought it was a great way to tag Antman back into Civil War. It is actually a trimmed down/excerpt from a Cap3 scene.