GROUNDLOOP.
To arrive from behind the display crowdline, display items need a special dispensation from the CAA. The Red Arrows have this dispensation. Can't think of any other recent items that have this, and, as said, the Ramstein aircraft that caused the disaster was flying towards the crowd, and flew through, rather than underneath [as planned] the main formation. The other two aircraft that crashed as a result were along the display line.
Perhaps my argument now makes sense?