After scooping plenty of ice into the bucket, John walks back to the suite with the bucket visibly empty.
As John and Elena run toward the hotel, a bus is passing as they approach a street to cross. When the camera angle changes, the bus has disappeared.
When John and Elena are out in the cold, their breath isn't visible, even though it is snowing.
Elena faints. When John picks her up, she lifts her knees before his hands slide under them.
At the airport, the boom operator holding the boom mic is reflected in the glass.