Warren Buffett's Kraft Heinz deal was unlike any Berkshire has done. He may not want to repeat it.

When Warren Buffett's Berkshire Hathaway teamed up with private-equity firm 3G Capital in 2013 to acquire Kraft Heinz, the billionaire investor faced questions about doing a deal with a PE firm, an approach to dealmaking that Buffett had long criticized. He insisted it was different. It doesn't look that way now.