Sounds like early onset. Unless someone is doing him dirty.
Report: Ex-Raiders OC Kelly would repeatedly call plays incorrectly:
Kelly repeatedly botched play calls, leading to dysfunction in the offense, reports NFL Network’s Tom Pelissero. The 62-year-old reportedly called plays that weren’t installed in the Raiders’ offense or in the game plan. He would apparently also forget to tag a motion call for wide receivers, confusing quarterback Geno Smith at the line of scrimmage.