"A formal ritual involving both/all pilots present on the flight deck, sterile flight deck with no distractions from CC or ground staff, would help to stop this one dead.
Yip. I agree , especially if emphasis is put on the importance of the calculations being made independently with a comparison only occurring once the final result is at hand.
Also, often times now days the ground staff are on minimum wage, minimum training, maximum workload ( turning more aircraft than they used to) and have no idea that distraction on the flight deck during this phase can be lethal so it is up to the pilots to enforce this sterile flight deck environment if the cabin crew don't. It is another example of how safety is slightly reduced each time an accountant has another brilliant idea about " lean operations" and implements it with no real understanding of what makes airline flying safe. I am all for efficiency and working hard but we are reaching a point where our enviable industry safety record will be tarnished on a regular basis if we don't act ( read spend money) when our SMS 's start squawking.