Black Panther Spoilers: 10 Major Plot Hints In The Trailer
10. Everett Ross Has Changed Sides?
In The Trailer
We see Everett K Ross - in the comics established as a diplomatic envoy who is assigned to T'Challa who helps preserve the sanctity of Wakanda - interrogating a captured Ulysses Klaue, picking at what he knows about Black Panther's nation.
You could initially think that he's trying to find out what he knows about the country to try and follow Bucky's tracks (since he has worked for the government), but since T'Challa is watching on, something else is going on here.
What It Means
In Captain America: Civil War, Ross worked with General Thaddeus Ross' pro-registration forces and brought Captain America and Falcon in Vienna, which suggested his political allegiance would have been aligned with Iron Man. Now that Civil War has "ended" and Black Panther has switched sides and taken Bucky in, it seems that Ross has too.
So, as in the comics, it's more like Ross is working FOR T'Challa, rather than primarily for the government and it's unlikely he still directly reports to Martin Freeman to Thunderbolt Ross as Deputy Task Force Commander of the Joint Counterterrorism Center. He presumably still wants Bucky taken in, even with his name cleared for those specific acts of terrorism.