At one point during the nightclub scene, about 53 minutes in, the shot is flipped, and the bassist is suddenly left-handed.
Miles Davis' blazer is spotless when cops beat and arrest him outside the nightclub for "loitering." His blazer is suddenly full of blood stains in the next shot when he is in the cop car.
Various scenes show Miles playing trumpets apparently made by Vincent Bach Corp., Adams, and others. But he never appears to play a Martin Committee trumpet. Miles played various customized Martin Committee trumpets almost exclusively throughout his career.
A scene in the film depicts the events of 26th August 1959, when Miles Davis was viciously beaten by two policemen outside the Birdland club in Manhattan. Davis was at Birdland as the leader of the Miles Davis Sextet, consisting of Davis (trumpet), John Coltrane (tenor saxophone), Julian Cannonball Adderley (alto saxophone), Wynton Kelly (piano),
Paul Chambers (bass) and Jimmy Cobb (drums). The scene inside the club shows Davis performing the song Blue in Green with a sextet, but the pianist is apparently Bill Evans rather than Wynton Kelly - he is white, unlike Kelly, and is addressed by Davis as 'Bill.' He is also depicted performing Evans' recorded solo at the end of Blue in Green (a song on which the full sextet does not play, and which Davis is not known to have ever performed live). However, when Davis is shown outside the club moments later, he stands in front of a poster advertising the Miles Davis Quintet, featuring Davis, Coltrane, Chambers, Red Garland (piano) and Philly Joe Jones (drums). This quintet was disbanded in April 1957, almost two years before Davis and Evans co-wrote Blue in Green, and almost two and a half years before the incident outside Birdland (The five musicians did briefly reform as a sextet, with the addition of Adderley, from January to March or April 1958). Additionally, like Wynton Kelly, Red Garland was black, meaning the pianist shown playing in the club could not have been him either.
In the end we see a Korg Kronos keyboard which was released in 2011... Davis passed away in 1991.
During the orchestra recording session for Porgy and Bess, Gil Evans is conducting out of time.
The movie is set in 1979, but the Jaguar has a high-center brake light, which makes it a 1986 or newer model.
The film is clearly set in the late 1970s, when Miles was not playing, and before he released The Man With the Horn (1981). A number of scenes in his basement studio include a Marshall Micro-stack amp, which was first manufactured in 1985.
At around 45:30, young Miles Davis directs a big band in the studio. The egg-shaped microphone with that green plastic around it in front of the trumpet section is an AKG D112, produced from 1989.
At the end of the film, Miles Davis is portrayed as wearing a vest that has the Twitter-related "#socialmusic" on its back. Davis died in 1991, but Twitter wasn't started until 2006.