T The fact that someone let a tree worth thousands of dollars die is more a shame than setting it on fire afterwards...
Unless you can get that the tree was dead from the text, I think it was destroyed in anger. "but the Valencia burn more expensive things in the failures and nobody says anything" I take to mean that passionate artists sometimes destroy their works because they are not happy with it. Heavily carved furniture burns well and marble sculptures shatter when pushed over. Maybe this was just tree that died but could just as easily been alive but "flawed".
I don't think that small of tree would produce that kind of flame on it's own no matter how dry it was. Dead or alive, I think an accelerant was used.