sw733 From United States of America, joined Feb 2004, 6324 posts, RR: 9
Reply 1, posted (3 years 5 months 1 week 3 days 23 hours ago) and read 3266 times:
"Earn miles when flying on British Airways marketed and operated flights for travel on an eligible published fare ticket. Miles are also earned on British Airways codeshare flights operated by oneworld carriers and oneworld affiliates."
Correct me if I am wrong, but Aer Lingus is no longer a oneworld affiliate, so you would not be given miles despite the BA flight number.
That's an interesting question. Generally, Star Alliance credits based upon the metal you fly on, but oneworld credits based upon the airline code on your ticket. Two different ways of approaching codeshares.
An example of a Star Alliance anomaly is TK8000, a flight operated by Malaysia between IST and KUL with the Turkish code on it. There are many threads on other sites that state because of the way *A credits flights, TK8000 doesn't earn miles in *A accounts, unless Malaysia is a partner of the airline where you're crediting miles (ANA I believe is one).
I'd submit it to AAdvantage and see what they do with it. Post your results!