Pop-tarts and Stupidity

Ted Frank, whom I've known electronically since the old rec.sport.baseball early days of the internet, just posted a summary of an intriguing civil case in which a plaintiff left his house briefly, leaving a poptart unattended in the toaster. The poptart caught fire, and the house was damaged.

So now the poptart-deserter, along with his insurance company, are suing the toaster maker! Is this another case of, "No matter what happened, it's not my fault!"? I don't believe it!

Okay, you econ-law types, who is the least-cost bearer of this risk?