I don't think the Ibiza accident was to do with changing selections after gear down. I think it was more to do with the fact that one of the brake computer channels had failed during flight and then the other one failed but only one registered as a fault. They landed in low autobrake so nothing much happens at the beginning anyway, and it was a bit late that they realised they had no brakes, and overran the runway. No doubt the passengers wanted a beach holiday, what more could they want than door to door service and a free go on the slides?!
(No pleasing some people......!!!!). Sorry, I shouldn't make light of it.
I think after that the autobrake had to be armed by pressing the pb for at least a couple of seconds after this incident and A320 crews had to reset the "anti-skid and nosewheel steering" in flight, to ensure both channels were working.
Think its all fixed now though.