A filibuster, in the context of foreign policy (as opposed to a political tactic), is someone who engages in an (at least nominally) unauthorized military expedition into a foreign country or territory to foment or support a revolution. The term is usually used to describe United States citizens who fomented insurrections in Latin America in the mid-19th century (Texas, California, Cuba, Nicaragua, Colombia). Cyril's coup also mimics the most famous American filibuster, William Walker, who proclaimed himself President of Nicaragua in 1856.
Gustavo Calderon blames what he said on 'pruno', which is the name given to wine made in prison, typically in a toilet.
The silver car Archer drives from the Palace is the 1968 Bizzarrini Manta Concept, designed by Giorgetto Giuliano. Lana drives a red 1969 McLaren M6GT.
Cyril is seen devising a plan to defeat the Rebels, using the pincer movement similar to the one used by Hannibal during the Battle of Cannae. He also mentions a member of his "Warhammer Guild" using the tactic, possibly a reference to the Warhammer tabletop game.