I think EK and AA's interline agreements (including ticketing, baggage, staff travel, everything) ended May this year. About the time AA and B6 ended their agreement and then later B6 and EK started their cooperation. And EY and AA started...

The OP may have been in a situation where he booked the ticket before the ticketing agreement expired, thus no rebooking on AA connections as per the original ticket would be possible. Still, with some more effort agents at transfer counters could likely have found you a way to get to AUS either via B6 or their other interline partners in the US via another gateway.

As other posters on FT will tell you, the ticket means they should get you to the final destination, the punctuality of that arrival might be a bit off though...!

If indeed it's a situation where you booked a ticket then afterwards the AA interline agreement expired, I think EK dropped the ball with you big time (either not rebooking you on another flight just in case you missed a connection like this) and not honoring the destination. Also, the agents you spoke with - big thumbs down for them for not realising a special situation here (they would try and rebook that in the system and the system would throw up an error - as it couldn't ticket another AA flight on the fare you were on which doesn't exist any more) and not calling a senior person who actually knows what they are doing when it comes to ticketing and EK's agreements to come and help you. Especially as you are a platinum member where I would hope they would at least pretend to try and be helpful...

Regarding going back to KWI - if this was a normal missed connection situation, I would have said you were out of luck and yes, buying a ticket back to KWI would have been the only option due to the whole web of fares and conditions on tickets (and then to claim on travel insurance) but in this situation, I think EK handled this exceptional case very poorly and goodwill and good customer service would I think dictate that sending you wherever you wanted to go within reason would be a good thing to do.

I think you have a good case for lots of compensation here OP, but you will have to escalate this via your local sales offices and directly with EK as much as possible.