The TV adaptation replaces the original "valet" accomplice with Saunders , the Opalsens' chauffeur.
A formal analysis titled "Poirot Investigates The Jewel Robbery At The Grand Metropolitan" examines Poirot's use of logical reasoning and interview techniques. It explores how his methodology remains relevant to real-world investigations while acknowledging the "supernatural" level of deduction often present in fiction. [S5E8] Jewel Robbery at the Grand Metropolitan
For a deep dive into how the episode was expanded for TV, the Poirot Project review details several major changes: The TV adaptation replaces the original "valet" accomplice
"Poirot" Jewel Robbery at the Grand Metropolitan (TV ... - IMDb For a deep dive into how the episode
In the original story, Mr. Opalsen is an oil mogul; the TV version changes him to a theater producer to add suspects and drama.
Analysts note that the recurring "Lucky Len" gag was added specifically for the show to give Poirot a reason to finally take the case out of annoyance.
Some reviewers from Styles of Dying critique the episode for its "clichéd denouement" and the logistical improbability of the heist's timing (requiring the theft to occur in just a few seconds). Plot & Mystery Breakdown