Your link deals with cigarette butts igniting brush on the roadside and hay in a lab simulating roadside conditions, not lumber. Nobody here is claiming that cigarette butts can't light dry brush on fire. I am claiming that in less than "freak accident" or laboratory conditions it is basically impossible to ignite lumber with a cigarette butt unless there is something (like dry brush) in between.

Edit: Based on the down votes I'm illiterate, I'm wrong or this is Reddit.