Spoilers below so if you havent watched it please don't continue reading......
I feel certain that it was the wells that gave up her location. No way he just sat there after his mistake and his character is due for a very heroic moment. He really hasn't done anything. That technology is also key as it just got introduced and he clearly had a plan, as did the rest of the group that the show purposefully left us in the dark with.
Plus, it would be stupid if she dies that way. I mean they could have easily just put iris in the building where the power dampener was until they figured out a way to deal with Savitar. If not that, they also could have erased Barry's mind again....he was learning to be flash again and his relationship with the group (especially Iris) would have been fine lol.
There were too many ways they could have avoided her death in that way, which is a shame because it was a great episode. It would be a more powerful moment if it was truly utter failure.
I also think there's something important to what capt. Cold said. He said something about Barry being good is his strength and not to fight Savitar at his own game. I think that's foreshadowing something.
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