Sokol resigned after failing to disclose a stake in special chemical company Lubrizol, which he built-up shortly before recommending the company to Berkshire Hathaway as a potential acquisition. Sokol had previously been considered by outsiders as a key part of the Buffett succession plan. Buffett did not let one blemish get in the way of his business decision and he still went ahead and closed on the Lubrizol acquisition.