http://www.herpsofnc.org/herps_of_NC...s/anurans.html

My best guess is it was a dark hued american, oak or fowlers toad. Some of their colorations can be dark, almost charcoal black (I have one American toad from Floridia that rarely ever lightens and is always black). The white was probally warts or maybe it was a male and she saw his lighter throat? He could also have had dried out skin or was starting to shed perhaps.

If she means jet black I don't see any species that dark in your region, even frog wise. Good luck recapturing it!