Is Captain America's "dark side" line in Age of Ultron reference to the Civil War?

Question

During the events of the Avengers: Age of Ultron, after Wanda has played with the main Avengers minds, they end up in Hawkeye's safehouse to regroup. In the yard, Cap and Iron Man are having the following discussion, while chopping woods.

Steve Rogers: Sometimes my teammates don't tell me things. I was kind of hoping Thor would be the exception.

Tony Stark: Yeah, give him time. We don't know what the Maximoff kid showed him.

Steve Rogers: "Earth's Mightiest Heroes." Pulled us apart like cotton candy.

Tony Stark: Seems like you walked away all right.

Steve Rogers: Is that a problem?

Tony Stark: I don't trust a guy without a dark side. Call me old fashioned.

Steve Rogers: Well let's just say you haven't seen it yet.

Script from wiki fandom

Is Cap's last line, reference to the events of Civil War that will follow?

Answer 1

Is Cap's last line, reference to the events of Civil War that will follow?

There's no reason to think so.

Cap doesn't turn dark during the events of Civil War, in fact he sticks to his exacting principles of honor and justice rather than submit to an authority in which he does not believe.

If anything, it's Tony who does the turning but that's a matter of opinion.

The simple fact is that Cap and Tony were on different sides of an argumement, neither side was wrong and neither was right but the reason for the disagreement led to an unfortunate series of events.

Answer 2

One possibility would be that Cap is referring to the secret that he is keeping from Tony, that Cap knows hydra ordered a hit on Tony's parents. Cap wasn't able to lift Thor's hammer; this is a strong theory why, which it could also be what steve was referring to as his dark side.