The song "Que País É Este?" that appears in the film was the album version released by Legião Urbana in 1987. Though it actually existed by 1984-5, (as it was composed in 1978), it could only make sense if a demo or actors performance was included.
The song and music video of "Homem Primata" by Titãs is shown during a montage during the 1985 segment, though both came out in 1986.
A Rock in Rio sticker appears on a studio wall during a sequence that happens in mid-1984, and before the event being mentioned in the story.
During an inner monologue Luiz mentions a lyrics excerpt from "Pense e Dance" ("happiness is an imaginary state"). Since the film isn't told from a future perspective, there's no way that Luiz could have quote an 1988 song in 1985.