Find out who stole the cookie

Task notes

• Also on the table, there is an empty glass cookie jar, and a magnifying glass.
• Paul has cookie crumbs on his bow tie, and a mouthful of cookie. He also has some chocolate chip cookies in one of his pockets, as well as a receipt from 'The Biscuit Palace' proving that he'd bought them himself.
• On the floor of the lab, there is another receipt for a NZ$17 cocktail named Trial By Cherry, from a cocktail bar named Bar Poisson Rouge [Red Fish] (note: the cashier on the receipt is recorded as season 3 contestant Justine Smith [who just happens to have red hair, which sounds like 'red herring']).
• The bar in the Taskmaster house has been dressed to play the part of Bar Poisson Rouge, where the contestants may find a half empty cocktail glass along with a red earring [sounds like 'red herring'], and a napkin upon which there is a lipstick mark and the text "Scarlett Wigs 022-035-4306" [scarlet wig = red hairpiece, sounding a little like 'red herring'?].
• If the contestants call the number on the napkin, a phone rings inside a purse in one of the contestants' lockers. Inside the purse, there is also a note which says "Go back one tife. Guilty Man Carmine Audiology - hearing." [going back one letter on each of the letters of 'tife' turns it into the word 'shed'; the guilty man would be the culprit, carmine is a red pigment, and audiology relates to hearing (which sounds like 'herring')] and also a key.
• There is also a cookie with a bite taken out of it inside one of the other contestants' lockers.
• On the desk in the study, there is a document titled 'SECRETS' which otherwise appears to be completely blank.
• The contestants may also find a note which reads "Thanks for buying my book. I know you're gonna love it. - Geri Hern".
• There is a fake book titled "The All Cookie Diet" written by a Dr Geri Hern [anagram of 'red herring'] on one of the bookshelves in the study, inside of which the contestants may find a box with a 4-digit combination lock.
• Also in the study, there is a fishbowl with a painted sign inside it which reads 'Red Herring'.
• In the bread bin in the kitchen, there is a locked box which requires a key, and is labelled as being "PROPERTY OF PAUL'S SECURITY SERVICES".
• The caravan has a sign on the door which identifies it as the office of Paul's Security Services. Inside the caravan, there is a VHS cassette player and a small TV.
• The shed is locked with a padlock which may be opened with the key from the purse.
• Inside the shed, the usual New Zealand fish poster has been replaced with one featuring solely images of red herrings. There is also a sign reading "Finish the gardens early" and "I left you a slice in the bread bin", plus an ultra-violet torch.
• The UV torch can be used to read the combination lock code written on the document in the study, which turns out to be '0000'.
• Inside the box with the combination lock, there is a key with a fob on which is written "PSS" [an abbreviation of 'Paul's Security Services']. This key opens the other locked box which was found in the bread bin.
• The contestants may find a VHS cassette inside the locked box which, when played on the VHS player in the caravan, reveals CCTV footage of an actual red herring stealing the cookie from the jar.