Lee Hye-in receives a facial gash along his left cheekbone thanks to a knife during his fight with Big Dipper, but for the rest of the film there is neither scar nor skin discoloration upon his cheek.
When Kang Dae-ho arrives at his new home (at around 11 mins) he looks at the motorbike which is a Ducati. Later on when he leaves the house with it (at around 21 mins) the sound of the motorbike engine is of an inline-4 motorbike. The Ducati (Monster) he is riding should have a totally different sound of a 90-degree v-twin, a well known Ducati low rumble, not the buzzing inline-4 sound we hear.