This "put your quality control where your mouth is" approach seems to be quite common in history. I remember reading somewhere (and take this with the level of credibility deserved of sentences beginning with "I remember reading somewhere"), that in the English Civil War all breastplates had a 'proof mark', which was the dent made by firing a pistol shot at the armour at close range, while it was worn by the armourer.

Edit: This may well be the origin of the term 'bullet-proof'