That does not look fun. But its the real definition of "Dumbass" decision. If you got stuck in mud, how do you think you would make it through a lake?????
But clearly, they were trying to ferry the Toyota LC across the lake with the amphibious APC. The LC raised the center of mass, making it unstable and causing the whole thing to capsize. Engines, transmissions and electrical systems in both vehicles will need lots of work.