The couple in the restaurant behind Ted and Robin really did get engaged during that scene.
Although mispronounced, Barney's statement about Ferrocarriles Argentinos (Argentinian Railways) is very accurate.
At the end of the episode, Lily French kisses Marshall in spite of Alyson Hannigan's request to not have to French kiss Jason Segel due to his smoking habit.
This episode (Something Blue) and the previous one, "Something Borrowed", mirror the "Something Old" and "Something New" episodes one season 8.
Argentina is mentioned 19 times (Including Barney's variation "Argentinian" (x2) and "Argentinos").