The sunburn on Karen's chest and arms appears and disappears from scene to scene.
McGarett's seat belt is clearly not fastened as the chopper takes off.
While driving in the car with Kimo, the Ala Wai canal can be seen out of Karen's window. But, when the camera switches to Kimo in the driver seat, the Pali (mountains) can be seen in the background. The Ala Wai canal is in Waikiki. There should be condos seen out of the driver's side window.