I think that many of us want to live in a world where multiple recordings are considered a good and normative idea, and the only way for that to happen is if we actually go ahead and act in that way.

To my way of thinking, the best approach is for you to contact the other podficcer and say, "Hey, the author said that you were planning to record this story. I've done a recording myself, and I wanted to know if you wanted me to wait so we could do a simultaneous release, or if you were pretty close to done and wanted yours to go out first, or where you are in your process?"

And then you've got to let the other podficcer deal with her hurt feelings, if she has them, herself.