I am certainly no expert but this seems highly implausible. To have a major forest fires I think you need certain conditions which don’t exist in Europe or in most of the US. The forest has to be extremely dry for a long period and those conditions don’t exist in most of Europe or the US. Not sure about Australia.
This was ONE incident of suspected arson:
Wednesday, October 24, 2007
Santiago fire feasts on brush in national forest
Chaparral and erratic winds in Cleveland National Forest pose mounting challenge.
THE ORANGE COUNTY REGISTER
Flames this morning are feasting on torrid chaparral and brush in the Cleveland National Forest, vexing battle-worn firefighters and heightening concerns that the Santiago blaze will put up a long fight.
While an ever-growing brigade of firefighters has scored major victories by managing to spare all but 14 homes, the inferno marches on, devouring 26,000 acres of land, blackening the sky and now inching steadily toward Riverside County and untouched Orange County cities.
ALSO:
August 7, 2007
FEDERAL AUTHORITIES CHARGE 10 FOR STARTING WILDFIRES THAT BURNED HUNDREDS OF THOUSANDS OF ACRES
Criminal charges have been filed against 10 individuals and companies in relation to wildfires that burned hundreds of thousands of acres of national forest land across Southern California, United States Attorney George S. Cardona announced today.
http://www.usdoj.gov/usao/cac/pressroom/pr2007/101.html