The events involving Angus McCullough -he found out his wife was having an affair with a local fisherman and murdered him out of rage, his wife resulting accidentally killed in the onset struggle, and then he ended up committing suicide by jumping off the lighthouse's balcony- DID happened; however, the real two surprises were:
It is then that Brian catches her, drugs her, ties her with chains and tries to have her drowned in the sea; luckily enough, she wakes up and manages to get ahold of the key just as both Brian and Sharon toss her off a boat and go see about lights on at the lighthouse. She unties herself, swims out and goes to have her revenge against them.
At the lighthouse, the three of them get into a fight, during whose struggle Sharon hits her head and dies (just like Angus's wife), and Brian chases Rachel to the balcony, only to cross way with the ghost of Angus -who possessed Patrick, when he returned to the lighthouse earlier-; he gets impaled by the hook and killed (just like Colin). Then, Angus goes to the balcony, gives Rachel the empty shell they buried together before, and repeats his suicide act of seven years ago, thus finishing Patrick as well. Rachel survives, is safe, and comes clean off the subsequent investigation.
In the end, the psychic lady comes and tells Rachel that she should "let go of Thomas's (Beans Balawi's) death and remember his life, instead". She is shown back in London at her old house, remembering where her son was found dead.