When Becky adds a splash of root beer to her tornado at the counter, the glass is very close to being full. As soon as she sets her glass on the kitchen table, the glass is obviously less filled, however she has still not taken a drink yet.
When Becky and Dana are lying on the couch drunk and Becky starts talking about a previous school year, her liquor glass is not in her hand. But when the camera cuts back to Becky after Dana says the room is spinning, the glass suddenly appears in her hand.
When Darlene comes in after basketball practice, she tosses the ball towards the closet door, only it hits the window and the sound of breaking glass is heard. This matter is never addressed throughout the rest of the episode.