My name is Derek, Spelt the same way too....
Whenever you mention this housemate of yours i think you are talking about me,
I've only ever met one Derrick and he had a different spelling.
Microwaveable Hotdogs seem a strange choice, I would've gone for those microwaveable fries because the cardboard box would've added more to burn with, a packet of hotdogs, I dont see burning too well.
It might not have been to burn down your room, but maybe just to fuck your microwave