The article says the article was actually available on site through a different publication, but the mechanic wasn't aware of this(and yet did the right thing of contacting dedicated support, who didn't advise him correctly):

" The Rolls Royce SBs were also listed in the Trent Illustrated Parts Catalogue, accessible from any computer at the facility, but he was apparently unaware of this, so he instead switched to plan B and called the Air Transat Maintenance Control Center for help."