Discussion of hacked bases is not allowed on the forums. But this thread blurs the lines since it's more of a question rather than a hack report. I've never seen such a long ghost run for a base that was not saved legitimately.
The jump was indeed possible a long time ago. It was one of the "super jumps" that were removed from the game. Basically you had to hit the corner of the terrain just right so you could get enough height to reach the chest. Solutions with these jumps can no longer be saved, but old bases use the physics that existed when they were created. This is what Unique referred to as a museum base. But if it's a museum base, then what's with the long ghost run?
The ghost is confusing to me, regardless of whether it was not saved legitimately or is an actual museum base.