Mr. Monk and the Employee of the Month - S3-E7
Plot hole: Monk wants to take a look at the case that got Christie to leave the force. But given that they are ordinary cops they would not be able to just go and pull internal affairs files.
Suggested correction: I'm not sure what you mean by "ordinary" cops. Captain Stottlemeyer is the one pulling the file. Plus, we don't see what they had to do to request access the files. There's no indication they just went in and randomly pulled the file with no authorization.