What was the outcome of that incident? Fault was found with the Air Canada procedures, training, and manuals, while the Captain and First Officer went on to receive FAI Diplomas for Outstanding Airmanship. What did not happen was mass calls for the individual pilots to write their own calculation software. I'm not sure what point you're trying to make here, as reading about the incident you mentioned only paints a clearer picture that systematic redundancy is the responsibility of the creating and maintaining the system, not of those using it.