The last couple of days, I've noticed that most deleted answers had a single undelete vote. To see if this was a coincidence or not, I deleted my last SO answer, hit refresh and saw that it too had a single undelete vote just seconds after deleting it. Why is this?
There were 2 bugs in the count preloading compared to how it worked before, remedying one of those the other day exposed another. Both are now fixed, this will work correctly after the next build.