I second that. When I looked on the "Last day" list, there were about half a dozen threads which had a post by that poster listed as the most recent post on them between 12.51 and 3.00, but when I looked at the threads themselves, those were not the most recent posts - in fact they didn't exist, nor was there any indication that they ever had existed. This look was at just before 14.28, so there had been a long enough time between the middle of the night and early afternoon or the reference to them to disappear as well as the posts themselves. Also, there is usually a note in the thread saying that a post has been deleted.
I've just looked again, and almost all of the threads were old ones which the strangely-named poster must have resuscitated.