When Phoebe first reaches Claudia on the shelf, she says to run "before Gammill sees us." However this is before Gammill's name is revealed.
In the scene where Piper finds Paige with Finn, Piper's hair goes back and forth between having a couple of strands down on either side of her face and those strands being behind her ears from one line/shot to the next.
Piper, Phoebe, Paige, and Claudia are completely covered in clay, but once they are able to escape it, there is none on their hair.
Phoebe tells the interviewer that she had to take a break from college after her freshman year. When she went back to college, she only did 2-3 semesters before she graduated. With all the demon hunting, she couldn't take more than a normal load of classes, so she couldn't have stopped after her freshman year and graduated as quickly as she did.
When Phoebe and Paige plan to go to the 'creepy house,' they agree to meet around 4. Paige goes back to work, and Phoebe heads right over to the house. There is no reason for Phoebe to head right over if Paige isn't meeting her for hours.