 The use and non-use of supplementary oxygen was the focus of much discussion and analysis after the disaster with a guide and a sardar both being criticized by Jon Krakauer for not using supplementary oxygen while performing guide duties.Both men gave detailed written explanations as to why they preferred not to use oxygen but both carried a bottle on the summit day that could be used if it was needed in an emergency or extraordinary situation.As declared by Boukreev in his book The Climb, he shared this explanation with Mark Bryant, the editor of Outside Magazine