Well, if you think about it, the shard are not "resets", each one is a paralel world that if are created too often create ripples that affect all the shards as "deja vu" flashback moments.
Even if Satoko is playing deaf to the reality, shes literally dooming many of her friends not only to death, but also to live with that permanent thrauma for those who survive. I think those scenes are showing that: Current Rena might not remember that specific scene, but Satoko did screw up some Rena's life permanently while killing most of the village alongside the way which is a terrific act