The signalling technician who had done the work had not cut back, insulated, nor tied back the loose wire and his work had not been supervised, nor inspected by an independent person as was required. In particular, a wire count that would have identified that a wire had not been removed was not carried out. There had been inadequate training, assessment, supervision and testing and, with a lack of understanding of the risks of signalling failure, these were not monitored effectively.