David decapitates a much taller opponent who was pinned erect against a wall with a level, chest-high swing of his sword. That angle could not have reached the foe's neck to separate head from body; it would have slashed the lower part of bigger man's rib cage.
The Chinese-speaking Singaporean office workers are listed in the credits as 'Japanese.'
Brutus is supposed to be a South African, but his accent is completely wrong.
The uniforms worn by the prison guards on the South African prisoner transfer are all wrong. Prison transfers are usually done by the police, who wear distinctive blue uniforms. Prison services wear pinkish-brown uniforms.
The South African prison vehicle is completely wrong. Prisoner transport is done in specially modified trucks.
Robben Island prison was decommissioned in 1996. Prior to that it was used as a medium security prison. Brutus Jackson would never have been imprisoned there as a high risk spree killer.
When Logan is in the corridor firing at David, a crew member can be seen on the right hand side of the frame, behind the wire.
The Brutus Jackson jailbreak scene supposedly takes place in South Africa, where vehicles have the driver's seat located on the right side. However, the bus and escape cars in this scene show the driver sitting on the left side.
Mere minutes into the film, the server goes down. The error notice is misspelled.