I ruled that an Erase From Time attack cannot be retried, but it only uses a single melee attack so that a high level oracle can attempt a second use of the ability in the same round in a full attack. The PC accepted the decision and the second attempt ALMOST worked.
An interesting analogy is the Inquisitor level 20 "final judgment" ability. There the inquisitor needs to hit and then the target gets a save. It seems clear that regardless of whether the inquisitor hits or not, one of the inquisitor's daily judgments is consumed in the attempt. By analogy, one of the oracle's daily Erase From Time uses is consumed in an attempt, even if the touch attack misses. I imagine that the inquistors and oracles are summoning their magic or juju or whatever as they strike out, and the magic or juju or whatever is consumed in the effort.