Yes, OE's guide is missing a clue at the police station. Missing that clue will likely result in getting 4 stars instead of 5.
How to get the clue: After you view the photos and perform Pinker's experiment in Tech Services, check out the desk that is behind the desk with the photos you already examined. On this second desk will be another magnifying glass you use to look at the microfilm, which is the missing clue.
OE is currently unable to update his guide with this clue, but Evokazz's guide has it included, so you can just follow his to get all clues and 5 stars.