You think that this is a copy of "Exit Music"?
Both songs have different chords progressions, "Bring Down" is played with a capo in 5th fret, and "Exit Music" is obviously without capo.
I think that both songs sounds more like "Hotel California" by the Eagles. And "Hotel California" sounds like "We Used to Know" by Jethro Tull. =)
Casuality? No, the songs are in Re Major, and if you studied harmony, you know that this a tipical chord progresion.