Mr Ash said it was possible he did not lock a reversing lever into place, which could have prevented the locomotive from slipping between forward and reverse.

BBC: North Yorkshire Moors Railway guard crushed by train

Mr Ash, a retired professional train driver with more than 50 years' experience, said it was possible he did not lock a reversing lever into place, which could have allowed the locomotive to slip between forward and reverse.

BBC: North Yorkshire Moors Railway death: Family to sue

Chris Hall, of the Rail Accident Investigation Board, said that Mr Lund would have had "no reason to believe" the train would change direction, which was most likely caused by the driver forgetting to lock the reverse lever.

BBC: North Yorkshire Moors Railway death: Family to sue