boukreev recorded that he reached camp iv by 17:00. the reasons for boukreev's decision to descend ahead of his clients are disputed. boukreev maintained that he wanted to be ready to assist struggling clients farther down the slope, and to retrieve hot tea and extra oxygen if necessary. krakauer sharply criticized boukreev's decision not to use bottled oxygen. boukreev's supporters (who include g. weston dewalt, boukreev's co-author of "the climb" (1997)) state that using bottled oxygen gives a false sense of security. krakauer and his supporters point out that, without bottled oxygen, boukreev was unable to directly help his clients descend, and that boukreev said that he was going down with client martin adams, but later descended faster and left adams behind.