Not underestimating the HF failures of the ergonomic layout, there are also confirmatory checks required that a control selection has been effective that may have prevented this - ie. the flap position would have shown that full flaps had not been selected. This guy was clearly distracted for a number of reasons, but the whole concept of CRM is that you are not acting alone. It's not like there were not other indications that something was not right in the cockpit. Before we redesign the Airbus, just consider how many thousand crews get this sequence of events right every single day.