BHP Billiton chairperson Jacques Nasser said the timing of its $20-billion spree into US shale in 2011 was a misstep and that if the miner could turn the clock back it wouldn’t have invested in the assets. The comments from Nasser, who will pass over the chairperson’s baton to its youngest director Ken MacKenzie on September 1, follow similar remarks from CEO Andrew Mackenzie, who said in May the deals were poorly timed.