All investors make mistakes. Give Warren Buffett credit, though, because when he was running Berkshire Hathaway (NYSE: BRKA) (NYSE: BRKB), on the rare occasions he made an investing gaffe, he was forthright about it afterward. Kraft Heinz (NASDAQ: KHC) was one of the Oracle of Omaha's errors. In what was supposed to be a "dream partnership," Berkshire teamed up with Brazil's 3G Capital in 2013 to orchestrate the $55 billion merger of Kraft and Heinz, creating what was then one of the largest consumer staple ...