During Hedwig's story about Tommy Gnosis, the level of Zima in her bottle increases between shots.
During the opening sequence, Hedwig's hair jumps about between shots.
In the Kansas City motel, Yitzhak wipes the left side of Hedwig's mouth; after the cut he's wiping the right side.
During the sequence in the trailer where the wall drops, the first shot shows the window on which Hedwig is stepping is closed. The second clearly shows it open by the curtain bowing towards the ground, and the third shows it closed once again.
On the poster advertising for auditions for a production of Rent (2005), the character of Collins is described as 'Young, Edgy, Black, Aspiring Musician.' However, Collins is actually a philosophy professor. The 'aspiring musician' of Rent is Roger.