Mr Roberts, of Wanaka-based Adventure Consultants, said yesterday that after climbing Everest, he had ''become embroiled in the arrangements'' to rescue the incapacitated climber from nearby Mt Lhotse.
Despite the efforts of Mr Roberts and fellow climbers, Taiwanese mountaineer Lee Hsiao-shih subsequently died. Mr Lee was in a state of ''hypoxic collapsed exhaustion'', apparently after having run out of oxygen on his descent from Lhotse three days earlier.
The climber, part of a guided expedition involving a different operator, had apparently been ''left for dead''.
''My mind reeled with questions, foremost was why had an effective rescue not been executed earlier?'' Mr Roberts said on the Adventure Consultants website.
Early on May 20, climbing partner Tendi Sherpa and he had arrived at Camp 4 Lhotse ready to help evacuate the climber to the Lower Lhotse Face, where altitude would permit a long-line helicopter rescue.
Fellow climber Kenton Kool had already spent the night in a tent with Mr Lee ''administering dexamethasone and oxygen in an attempt to keep him alive''.
''My arrival coincided with the emotionally charged process of confirming Mr Lee's tragic death.''
Although both ''emotionally distraught'', he and his friend decided they should attempt to climb Lhotse.
''Somehow I imagined Mr Lee would want us to do this in his honour and this notion spurred me on.''
The two climbers reached the top in just over four hours. Mr Lee's body had been retrieved, and Mr Roberts had since returned to Everest Base Camp.
