Continuity mistake: In S.O.S., Locke is trying to remember the map he saw on the blast door. He ignores the blaring alarm until Jack reminds him, and Locke inputs the code and hits EXECUTE. The camera cuts to a shot of the numbers resetting, and then back to Locke, and he takes his finger off the EXECUTE button a second time.
Continuity mistake: In episode 2-19 SOSWhen Bernard is talking to Rose after she questions him in front of the group about his "sign" when the close ups are on Bernard you can see that it is raining quite heavily in the background, but when it's close up on Rose it is not raining. It doesn't begin to rain in the episode until much later.