During the first bar scene Dennis' shirt switches between wet and dry multiple times.
When Mac storms out of the bar he throws his towel onto the barstool, where it falls to the ground, but in later shots the towel has returned to the barstool.
During the dinner scene with Charlie and Dee, the placement and level of water in their glasses changes from full, halfway gone, back to full with each shot.
During the first bar scene the length of Charlie's rolled up jeans switches from knee length to around mid-calf.