As I understand it, they are in a slighly altered reality.
O'Neill is waiting on Carter to pack her things to go fishing, with the rest, at his cabin. The hint is that in episode 17, they are fishing , but they know there is NO fish. In this episode, they say there are no fish, then one jumps out of the water. Thus the time line has been altered, but not enough to screw up the show.
I looked at eight as the end of the show. SelMac is dead. The good doctor Janet died at the end of seven. Hammond is gone. The replicators are gone. Ahnubis is finally gone.
The best one is Daniel keeps dieing and coming back. I think he has been killed more times than any cat.
And, The biggest reason is, there has not been single cobra in any epsiode ( at least I do not think so ).
