Failing a mission when an escort is disabled

I have a mission that grants an escort as a special ship. I need the mission to fail, abort, or otherwise go away when the escort ship is disabled. I have the mission ship set to protect the player and jump in after a delay. I've tried setting the player's goal to "escort" so the mission will fail if the ship is disabled, and setting the player's goal to "disable" and having the mission Axxx itself for OnShipDone.

However, the escort just won't go away when he gets disabled. If he gets disabled and I fly through a hypergate, there he is again, with full health. If he gets disabled and I land on a spob and take off again, there he is. Any ideas on what might be causing this and/or how to fix it?

Hmm that's very strange. In Anathema, I did the exact same things you mentioned and they both worked perfectly. All I can suggest is that you attach a placeholder dësc to fail and/or shipdone to make sure that part is triggering properly, then check your NCBs to make sure they're accurate.