"It was my department which actually developed the independent internal verification process," he recalls fondly. His straightforward, no-nonsense style won him many admirers within Shell, where he is widely remembered for his thoroughly professional approach, rooted in a deep belief in Shell's business principles and the need to put safety first. In 1996 he then moved to Shell International Exploration&Production (SIEP) in The Hague where he worked in a variety of posts: serving as a senior maintenance engineer (1996 to 2000); global consultant (1999 to 2001); HSE group auditor (1998 to 2001), and finally internal audit manager (from 2000 to 2002). He took early retirement from Shell in June 2002. During that period Campbell led between 27 and 30 safety audits for SIEP worldwide. "Probably around 50% of those were satisfactory and some 50% were not," he calculates. It was during that period, in 1999, that he was called back to Aberdeen to carry out the PSMR audit for Shell Expro.