This year’s Berkshire Hathaway meeting gave shareholders their best chance yet to hear from the man who will one day take over as CEO when Warren Buffett is gone, but Buffett said for the first time Saturday that Greg Abel should also take responsibility for the company’s investments after he takes over, raising new questions about the succession plan.

Abel put his encyclopedic knowledge of the utility business that he led directly for years on display and delved into railroad operations and potential acquisitions that Berkshire pursued while sharing the stage with Buffett all day. For his part, the 93-year-old billionaire showed investors he is still sharp.

Abel pointed out that it required a major culture shift to get workers at PacifiCorp and the other utilities, who have long focused all their energy on keeping the lights on, to think about shutting the power down at times when the risk that their power lines could spark wildfires is too great. He also said BNSF railroad is working on getting “our cost structure right” after delivering disappointing results.