A class 1 roof won't catch on fire, so sprinkling it is a waste of time (and water). One way houses burn is embers going through openings like soffits, attic vents, or windows that break from heat. Or flames on the side of the house melting the vinyl and burning through walls. If they kept the perimeter cleared then kudos to them. That's mainly what saved them and lack of openings.
There are still a lot of California homes with wood shingles or tar and gravel roofs or a combo. We had a big retro fit on our home and replaced a shake with some tar and gravel with the roof you recommended.
We spent thousands of $’s having dying 50 year old pine trees cut down and chipped and the planted brush/shrubs around our home removed and hauled away..
As usual, there is a lot of controversy re what to do. During our retro fit, our contractor installed 12 air vents on the sides over the foundation of our home for air flow and to prevent dry rot, fungus and other problems and to meet the code. In some areas, air vents apparently sucked in burning embers and set the homes on fire.
Thanks for your comments.
“Or flames on the side of the house melting the vinyl and burning through walls.”
This caused the loss of many homes in an area with a lot of shrubbery close to the house, even the stucco homes. In one area, they got the shrubbery soaked with garden hoses and apparently saved the homes.
The big home saver was swimming pools and a gasoline water pump.
The above happened last October and was not in the recent Paradise fire.