Although the blurb on the page for this episode (S7. E1) states "It's the first full case for DI Jack Mooney on the island", it is in fact his third case on the Island.
Episode S6. E7 also states that it's "DI Jack Mooney's first official case in paradise", this in fact is correct.
This is the second time Denis Lawson has lost his bride-to-be to murder. (Agatha Christie's Ordeal by Innocence (2007), 2007).