When a code share works to your advantage

Last month I was booked on the last BA flight before they ditched the route Gatwick to Fort Lauderdale. Booked with Orbitz using the AA codeshare so AA flight number and ticket number and BA flight
When I went to check in 24 hours before the BA app advised there would be a delay but didn't specify how long. I checked in and got seats allocated (was a hand baggage fare). Checking back two hours later the delay was posted at 4 hours due to delayed incoming aircraft.
Usually I'd rub my hands together and look forward to EU261 compensation as it was posted as technical but for this short trip I really didn't want a late arrival for various reasons.
I then called AA who advised me that their policy was to rebook if there was a better option (BAs policy is suck it up Buttercup) and as I was on the code share I could move to any of the earlier Heathrow to Miami flights with BA or AA at no charge as the delay was over 3 hours.
Done deal !
No charge to change to a Miami flight arriving at the same time as our original flight and when I called Number One to change the lounge they moved us to the Heathrow lounge (which is more expensive) for no charge and added complimentary champagne because "Its your birthday and you are having a bad day"
Cab to Heathrow is £20 more than Gatwick for me but well worth it in the big picture.

Code shares aren't always a bad thing