Did BA say they sent it to AA and AA had not posted it, or, as you imply, they said "not our problem?" It is their problem to transmit the points request or nothing happens on the AA end. There is still a purchasing of AAdvantage points on your behalf by BA.

A very patient AA person years ago explained to me its an electronic load and if the partner has never sent it its not like somebody at AA can look into the manifests of a partner airline and verify, or calls them up and argues on your behalf.