A building in Xinyi District, the Kelti International Building, represents the Kwang Headquarters but only in the opening scene. The original decals marking the building's address are shown in a later shot.
The salesman at the car dealership says that the Ferrari is a "488 Pista Spider", but the car is a 488 GTB, as shown on the dashboard in the car.
When he's at the fishing village, the DEA agent puts on his shirt. It has a big red blood stain from where he was shot, but there is no bullet hole.
During the flashback scene of John and Joey's last goodbye [1:09:40], the police arrive on the scene in vehicles that are clearly from the present time (2018+ Toyota Corolla/2017+ Toyota Camry), despite the flashback being set 15 years in the past.
During John's trip to Taipei, an establishing shot depicts a China Airlines aircraft approaching Songshan Airport instead of the main international airport in Taoyuan, Taiwan.