How do you jump over a castle wall?

Has anyone seen an invader do something like this?

I was playing co-op at the Shaded Castle on PS5 Pro, and an invader came in. My co-op partner saw him basically launch straight up into the air from inside the castle wall, clear the entire perimeter wall, then drop down on the other side and run around to get to us.

And I don’t mean he hopped over some small piece of geometry. I mean he looked like he launched something like 30 meters into the air and went over the full height/breadth of the Shaded Castle outer wall. I’ve never seen anything remotely like that in Elden Ring, and as far as I know there’s no Ash of War, spell, item, or DLC ability that lets a player do that.

Then when we actually fought him, it felt like we couldn’t hit him with anything.

Is there some known Shaded Castle geometry exploit, crazy desync issue, or PvP tech that can cause this? Or does this sound like cheating/save-edited nonsense? I’m not trying to witch-hunt anyone, so I’m not posting the name. I’m just trying to figure out what the heck we saw.