Sorry if this has been mentioned already. I have looked but could not see anything elsewhere BUT at the top f the hill there is some kind of pole. It is onscreen at 39 mins 46 seconds. First thought is an antenna but it doesn't look like one. Anyone else seen it?

Yeah, it looked like a set of loud speakers to me, similar to the ones they were using when they walked Jack over to the OR. Made me think that even at that remote part of their island they still have equipment present, like its one huge compound.

does anyone have a screencap?

Sorry Dino I don't think the quality of my er...'recording' would be clear enough. Hopefully someone on your side of the pond will oblige.