When Catherine raises her hands after capture, her thumbs are through holes in the sleeves from the front, but not when seen in the reverse angle from behind.
At the beginning of the episode, McGarrett has a full beard. When the others arrive to go with him on his mission, he shaves it off, but he immediately has his typical couple days of growth.
The French language used is grammatically all wrong. "Placer vos paris" makes no sense in French. "Faites vos jeux!" is what croupiers say in France. "Vous gagnez avec un nine" is not only incorrect, but unintelligible in French. "Vous gagnez avec un neuf" is proper French. (Neuf being French for nine, here.)
Although Steve gives the impression that Bama's plane is privately owned when it is later shown in flight it clearly has the paint scheme of the U.S. Coast Guard.
When Catherine drives off at the end, a shadow of the camera as it is rising is visible on the USCG C-130.
In the flashback where Greer and Catherine meet, Greer calls Catherine "lieutenant" even though Catherine is wearing an ensign's shoulder boards.