Teleporting Crursade

[DEB8]

So how did a) thier cursade stay in my territory after retreating

Not sure, but this part of the unusual AI workings seems similar to the way Rebels can operate. Perhaps Crusades ( and Jihads ? ) can operate in a similar fashion ?
Or maybe it's a Bug ( badly written piece of Program )...

and b) how did that crusade teleport to the other side of the Med?

The AI can run several Crusades ( to the same place ) at the same time, even for the same nation. Perhaps this was a different Crusade ?? Check out it's Leader / Units ( if possible ) to verify this. Also note my comment in the previous post re being able to see / not see applicable Shipping...