Syracuse sets an empty vodka bottle at his feet while on the island with the lighthouse. When he walks away from Ondine the bottle is still there. However, after a cut to show Syracuse starting up the boat and back to Ondine hearing the boat and jumping up, the bottle is nowhere to be seen. Ondine could have thrown it away in between, but there's no sign that she moved at all.
When Ondine and Annie first meet, Ondine is soaking wet and her dress is clinging to her on shots toward the water, showing Ondine from the front. On alternating shots, looking toward the house and showing Ondine from behind, she is barely damp or completely dry and the dress is not clinging to her at all.
Syracuse's hair changes length and cleanliness throughout the film. In the same scene his hair will be freshly washed and styled, then windblown and stringy.
During surgical operations hair is always covered as part of infection control. Annie's hair is not, whilst doing her kidney transplant.
When the drug smugglers are looking for the backpack it is revealed that Annie moved it to the lobster pot. This is impossible! Annie had no access to the boat and was not strong enough to pull the lobster pot out of the water.