DHARMA must have stations all over the world where they can conduct small experiments in remote locations. Charlotte seemed really pleased to find the collar, I don't know if she was expecting to find it (because of who she works for) or if she just stumbles on DHARMA evidence all the time in her work (and innocently tries to make connections).

When you see tiny details of anyone's life out of context they will really throw you. Add weird smoke monsters and Polar bears and the conspiracy/time loop theories set the internet on fire. I think in the end the big twist will be pretty obvious and more basic than we all imagine now. There isn't an alien invasion or anything too insane to worry about but I do expect some type of sci-fi twist.