Factual error: Simone is hit by a bus running after her niece. The bus is service number 106, however service 106 is Finsbury Park - Whitechapel and runs nowhere near Horseguards Parade, which is where the scene was filmed. Also the bus is operated by Sullivans Buses, when route 106 is actually operated by Arrivia. The depot code SM (seen on side of bus) is Potters Bar and not AE (Ash Grove) which is the actual depot that operates route 106.
Factual error: A number of times throughout the season they refer to LSD being found in dead bodies and LSD being matched with other LSD found in other (living or dead) bodies. LSD starts a chain reaction in the brain which requires about an hour to take a noticeable effect. And, by that time, it has completely broken down and no longer exists as LSD in the body - before the person even begins to get high. There is no test for LSD even in the most bombed living individual, let alone a dead body years later.
Factual error: The only person ever addressed as "Sir" is the brigadier, and then only occasionally. No other officers ever seem to be addressed in this way.
The Alchemy Murder Case File 3 - S1-E8
Factual error: The Latin text on the supposedly old tome (which is written with a modern font) displays an alchemist diagram. It is a reproduction of a famous drawing meant to portray the Philosopher Stone in the Sylva Philosophorum, but whoever copied it does not know Latin, because certain words are misspelled ("Merceralia" instead of "Mercurialia", "Humides" instead of "Humidus"). (00:10:10)