i've studied this carefully and can only think: "Colonel Mustard, in the library, with a candlestick."
here goes:
van dweller comes home after a rough day of vannin and has a cool brew. or two.
then, he gets the muchies and decides to cook up a batch of garlic edamame beans. he cranks up the burner and turns to have a toke on his brew.
unbeknownst to van dude (or dudette) the flickering flames have ignited the roll of paper towls precariously hung directly above.
as the flames grow - and here's the brillant part - they burn through the labyrinth o' water pipes, immediately extinuishing the blaze.
unfortunately, van dude's insurance company failed to see the humor in his recollection of the night's events.