When Johan Falk and his team watch through the secretly taped video of the villains admitting to their crimes, they complain about that they cannot use it as evidence since they lacked the proper paperwork before rigging the camera and microphones. As policemen in a Special Crime Unit they should be very much aware of that the Swedish legal system accept ALL kind of evidence. Even those that are obtained through illegal ways.
...a fact that you would think that both a policeman and a screen writer should know about.
When Lasse is copying the video files from the computer into Hanna's cellphone, he's actually only creating shortcuts. The videos should not have been able to play on the phone.