The day experts you refer to on a DD&C night are there for the duration the said activity alone. Correct me if I'm wrong, but this problem was only found once they tried to split out the sectors - not until way after the DD&C team had gone off to dream land after a job well done and all the boxes ticked. I'm willing to be proved otherwise as I wasn't there - I only heard the gory details the other night from a colleague. I think you under-estimate the skill and ability of the "technicians" as they have been called.