No, there isn't a call script for after battle actions. I don't have XP at the moment, so I'm afraid I can't help you that much.
However, to any scripter willing to help, the way I would go about this is make a list of actors in the party at the beginning of the battle (one of the starting methods), and make another list of actors in the party at the end of the battle (one of the ending methods), then compare the two and remove any added actors after EXP is distributed but before the party goes back to the map. Not very difficult, I would do it myself if I had XP.