They were seeing it as not sustainable, while we're actually seeing the first hiccups. As you may now know, finally the EIA admitted in its latest report that peak oil already occurred :
http://www.iea.org/w/bookshop/add.aspx?id=422
quote :"If governments put in place the energy and climate policies to which they have committed themselves, then our analysis suggests that crude oil production has probably already peaked."
Of course this didn't make the news. Keep on the denial, people.