In Catch-22 (2007), Naomi's helicopter crashes in the water, but in the subsequent episodes the freighter crew still has a helicopter, which implies that they had two before Naomi crashed. However, only one helicopter is present on the pad in this episode during the scene where Naomi is arguing with Frank Lapidus and Frank's scene with Kevin.
When Michael wakes up in the hospital, just before he hallucinates about Libby, he looks at the patient next to him and we see he's intubated (which means he should have been in the ICU ward, not a regular room). However, when the actual nurse comes in seconds later, that same patient is not intubated, but only has a breathing mask on.
Just before Michael (Kevin) walks on to the boat (25:45) you see a guy with his arm resting on a metal bar, in the next shot from a different angle as Michael get on the boat, the guy is gone.
Tania Raymonde's microphone can be seen hanging over her right ear as Alex and Danielle prepare to run after Karl's death.
When Michael arrives at the port in Suva, Fiji, the taxi is a left hand drive vehicle. In Fiji, cars are driven on the left hand side of the road, so the vehicles are right hand drive.
During the scenes at the Suva port, a large airliner is shown nearby taking off or landing. In fact there is no major airport near Suva capable of handling that size of aircraft. In Honolulu, the international airport is close to the harbor and was probably the source of that airliner.