I'm going to need some source for this

Not really that surprising, a lot of natural materials have really good insulating qualities. Considering that it's mostly cellulose and water, I wouldn't really really think it would be flammable unless dried out.

Any organic material will combust at 3300C given enough time

Ughhh imagine living in a house made of Durian!?!?

le leidenfrost effect

It is called "King of the Fruits" not for nothing, you know.

I tried to research that, but couldn't find anything. Seems they quickly rot, even at moderately warm temperatures. I have to call bullshit.

Breath of the Wild lied to me about durians.