Dead man's eleven goof?Poss spoiler.

Barnaby remarks that the religious couple seem to have rather poorly paid jobs and wonders how they can afford to live in an expensive village .We later find out that their lifestyle was funded by stealing a coin from a murder victim by abandoning her to go to her cottage to get it.However since the husband knew about the coin and was on friendly terms with the lady who was pushed over the cliff it supposes that he already lived in the village anyway without the benefit of the £100,000 proceeds of the stolen coin.