Originally Posted by The Endless
How is it a plot hole? It's two different films that are set in the same universe sure... but you can't say Cap not turning up in IM3 or Stark not turning up in TWS are plot holes. They are individual films.
It's like the comics. Cap's comics are individual stories in his little pocket of the MU. Same with Stark's and Thor's. Sometimes they cross over or team up, but those are usually in cross over events.
These solo films are like solo comics. The Avengers films are the equivalent of the big cross over events.
It's a plot hole in the overarching story. You could call it a plot hole in the Avengers franchise if you had to nail it down. The plot hole existing in the comics doesn't make it not a plot hole. Unless the movies explain them as pocket universes, then again, that's just fan theory.
Edit: According to IM3, the rest of the Avengers exist. Is it not referring to the characters from Avengers and their respectively solo films? If so, then the hole actually would be within the film, again, if not for Rhodey's subtle implication that the US wanted to handle it themselves.