This is the first of a two-part column. The second part will be published on Tuesday.David and Annette Garber’s strict liability claim against Amazon.com for extensive fire damage to their residence — allegedly caused when a motorized two-wheel contraption called a “hoverboard” that they purchased in early November 2015 through Amazon’s online marketplace from Shenzhen Gangshen Technology Co. in China spontaneously burst into flames — required U.S. District Judge Virginia M. Kendall to …