After the boat has tipped over, Matt has a cut that is bleeding on the right hand of his forehead. But a few shots later the cut is gone.
When the remaining trio swim towards the island, it constantly disappears from the shots that are taken from behind the group.
When the boat is capsized-some of the furniture remains facing upwards as if the boat didn't capsize-e.g. the hob faces upwards on the oven that is moved from the door.
When Luke enters the water before swimming into the capsized boat for supplies, he has no torch. However, when we see him inside the boat, he now has one. This happens twice - also, when he comes out of the boat the first time, there is no sign of the torch he was using - yet it reappears in his hand when he enters the boat the second time.
When he gets back into the water to swim into the over turned boat for supplies, there is a crew member already in the water.