Revealing mistake: Near the end it cuts to a scene where there is a small group of musicians playing classical music. In the centre is a male violinist playing but his bow is about 3 inches away from the violin.
Revealing mistake: When Han is firing the Gatling gun at Frank and Marvin, he is on one side of the street, firing across the street and through the parked cars. Frank and Marvin are lying on the ground on the sidewalk, but some of the bullets' exit holes (after shooting through the vehicles) fold inwards, when they should have bent the metal outwards. (00:49:30)
Revealing mistake: After Bailey stabs multiple people, there's no blood on the knife used at any point. (01:50:00)