When Monroe pops the champagne at the pool while Samantha is swimming in the pool, he pours a glass that is bubbling over the top. A split-second later he walks towards the pool, and the champagne is completely void of bubbles.
When Monroe and Zack are being announced in the finals, a shot of the stage and tournament bracket are visible with no names or results on the board.
When Monroe walks up to Samantha after winning Barnes court date, you can see Samantha's wire taped to her back.