If the mess is uncovered (ie. pissed off the wrong politician and/or their donors and have no political protection) SOX gives the legal avenue to go after the CEO and CFO and hold them legally accountible.
Level of risk and amount of responsibility in generating sales are two different things. For a CFO the risk is high because of SOX, responsibility to generate sales is often low.
SOX is the reason why Jon Corzine should not have a leg to stand on ... heck he sponsored the bill ... then again see first point above ...