The last, elderly shepherds start fires to clear thorny scrub and to promote green-shoot growth, "but they lack the physical strength or the manpower to control a fire, and it gets out of hand," says Pieter Van Lierop, a forest-fires expert at the FAO.
A second fire expert hired by Ori White, the new district attorney in Willis's district, concurred.
"There are no lightweight bombers being surplused anymore," said Vincent Ambrosia, a forest fire expert at NASA.
Remain fired "expert opinion" into the debate; leave fired back with the word "control".
It commissioned Craig Beyler, a nationally recognized fire expert, to examine evidence.
But one fire expert said that warning signs are not enough.
John Lentini, a fire expert and the author of a leading scientific textbook on arson, describes Hurst as "brilliant".
"So this fire is not even huge by historic standards," says Stephen J Pyne, a fire expert and professor at Arizona State University.
"Your vehicle insurer's fire expert shares a similar conclusion with respect to the cause of the fire," he added.
John Lentini, a fire expert who has studied flawed arson investigations, hammered at the evidence and analysis from fire marshals at the Willingham trial.
The defense had tried to find a fire expert to counter Vasquez and Fogg's testimony, but the one they contacted concurred with the prosecution.
