We have no idea what this was supposed to prove.
Have you ever watched a rally and wondered what the fuel economy figures for all of the cars were, so that you could make a more informed decision on which car to buy? No, you probably haven't, because the way the cars are being used is so different from how you commute to work. That information would be utterly useless. And yet, here we see Mitsubishi taking an Outlander plug-in hybrid through a whole 2,000km rally in Thailand and Laos.
While the use of a plug-in might be a little baffling, it's difficult to deny that the mostly-stock Outlander did a perfectly acceptable job of withstanding the rigors of the terrain, so it's not a total loss.