I don't know much about him. The book gets a glowing review at [link|http://www.amazon.co.uk/Last-Oil-Shock-Extinction-Petroleum/dp/0719564239/ref=pd_bbs_sr_1/203-7550792-3852716?ie=UTF8&s=books&qid=1175270901&sr=8-1|Amazon.co.uk].
Cheers,
Scott.
(Who agrees that it's a very strange statement. It seems clear that he's not a mathematician.)