Had a similar case at a certain former flying station near Huntingdon in 1990 - a SNCO who allegedly made away with footie club funds - fotunately discovered in my first week as OC Blunties Wg, not my last. Investigation not RAFP's finest hour, and prime suspect left on med gounds nearly 3 years later, to coincide with my departure on redundancy. All came to light because (having been on the Command Accounts team, and also three quarters of the way through Chartered Management Accountants course) I asked a stupid technical question on VAT. Interesting conversation with my new Stn Cdr (RIP Reg) on my first day as an acting paid wg cdr.
There was a cracker at Hendon many years ago (late 80s) - Mess Manager in the Sgts' Mess had immaculate account books, and everything was as it should be, until one thought about the meaning of what was there - for example, the sum written off to "drayman's drinks" (those were the days) represented so much alcohol that the driver would never have made it into the cab, let alone out of the gate. MM did get CM'd and put away as I recall.