In the bar scene where Ray and Charles are talking, they each have a glass of whiskey. They take drinks emptying the glasses. The next scene you see the glasses are empty. As Charlie is writing a note for Ray, one glass is half full. When Charlie slides the note to Ray, both glasses are empty. After Charlie leaves, Ray picks up the note and you see the glass is half full again. When Ray makes a phone call to Walter and the glass is empty again.