I dont think they died. I think what Richard was referring to was the purge
I dont think they have reset time, I think what just happened always happened. That was the indicent, I mean look at what happened to Dr Changs hand, it got stuck at hurt and in one of the dharma videos he has like a glove on I think or something that indicates its missing.
I think they have been sent back to 2007 where sun and locke are, and there is gonna be some war. They key is fake locke
