US Adopting AA inter-line baggage rules
AA will go as far as protecting the passenger (not just the bags) in the event of IRROPS between two separate oneworld tickets. I have the URL written down at home and can post the link later on. A google search is easier to find it than a search of aa.com.
I haven't had to invoke it yet, but it has given much peace of mind when buying two separate (but connecting) tickets for whatever reason. In my opinion, a huge advantage of oneworld over Star. Not sure what sky team does.