In a nutshell, the defect that causes the guns to fire when holstered occurs when there is a small amount of pressure on the trigger. If the slide (top part of the gun) is wiggled / nudged, it will fire. Also, the gun can fire when dropped. Both these issues are mitigated by other manufacturers with a trigger safety and longer trigger pull.
Also, does not help that the US Army does NOT want this FMECA document released. From the article that is cited the US Army's project manager & legal counsel gave this response to help Sig justify keeping the document sealed:
> The Army position would be to oppose the distribution to the public of the > FMECA document as it potentially reveals critical information about the > handgun (design, reliability, performance, etc.).
Of course the NRA pitched these laws to their members as protecting against gun violence victims suing the manufacturer, but they also slipped in that gun manufacturers have no legal responsibility to provide guns to buyers that do not fire unless the trigger is pulled.