I suggest you go to the 40 mile zoom.
That craft pops up out of nowhere at 12:54:30 at 2000 ft. By about 12:55:43 gained 200ft. At 12:55:56 it utterly disappears.
Makes no or little forward motion. Most of the motion is the icon shifting forward direction (nose pointing) with abrupt changes.
Strange, to say the least.
I don't feel expert enough to get involved with playing around with that web site, but I am interested in what people with some experience in air traffic control have to say about it. I'm not sure whether I can make discriminating evaluations without having spent many, many hours watching this stuff as it normally behaves.