When Livia leaves the hut for skinny-dipping in the ocean, she doesn't have a necklace but in the water she has a necklace.
In the beach hut scene the woman who takes her clothes off in front of Helmut and encourages him to follow her into the sea is a poorly chosen body double, with over-large breasts and neat sparse pubic hair, whereas the woman in the underwater scenes appears to be the real Livia with luxuriant pubic hair, neater breasts and a different pattern of moles on her left side.
The guy laying dead on the stairs blinks his eyes just before the switch to next scene.