Well the phrase "revalidate the ticket" definitely got AA to do something and the agent went ahead and did that. They told me I would get a new BA PNR emailed through - about 5 mins later I got the "Trip Confirmation" email from AA but the BA PNR has not changed and still has the same problem in BA MMB. I guess given BA's IT I'll wait until tomorrow before I assume for certain that it's still broken but not looking positive!