In the answers to this question: How can I change the view outside the main thread?
One poster felt that another had copied his answer. He claimed that the alleged copied answer had been edited, but there was no "Edited at XXXXX" notice next to the name of poster. He also has linked to another of his answers that he indicates was edited but also does not show this notice.
Is it possible that an answer can be edited and not be displaying this notice?