Continuity mistake: When Cheng watches Bu stick the note on the café window, no one else can be seen on the pavement in front of the café. When the scene is shown again inside the café, a father with a baby can be seen walking past the window, who were not seen the first time. (01:54:00 - 02:02:25)
Continuity mistake: Ling walks outside the cafe after Bu puts the note on the window. When the scene is shown from Cheng's POV, she stands still after walking outside, then walks a few steps to take the note off the window. When the scene is shown again from her POV, she is a lot further away from the window than earlier and has to walk a larger distance to reach the window. (01:54:20 - 02:03:05)