When Rob and Fab are given a cassette demo of the song "Blame It on the Rain", they are told that it was originally written for Whitney Houston. In real life, Diane Warren originally wrote the song for The Jets, but Arista Records president Clive Davis suggested to give it to Milli Vanilli instead.
When John Davis, Brad Howell, and Milli Segeith explain to the rest of the Milli Vanilli recording band who Clive Davis and Arista Records are, they mention Whitney Houston, Earth, Wind & Fire, Santana, Aerosmith, and Bruce Springsteen. Of those artists, only Whitney Houston and Santana have ever signed with Arista Records.
During the flashback in 1986, the Munich subway station has signage for the U8 line, which didn't exist at the time. The U8 line didn't start service until 2013.
During the 1986 photoshoot scene, Rob is seen wearing an Adidas jacket that uses the "three bars" logo, which was not introduced until 1990.