Postflight analysis described the PHS malfunction as "mission critical" but noted that the pilot "adequately compensated" for "this anomaly ... in subsequent inflight procedures," confirming that backup systems—human pilots—could succeed when automatic systems fail. Some memoirs, such as that of Gene Cernan, have revived the simmering controversy over who or what, exactly, was to blame for the overshoot, suggesting, for example, that Carpenter was distracted by the science and engineering experiments dictated by the flight plan and by the well-reported fireflies phenomenon: