I agree with the ruling, but for different reasons. Anyone that can't figure out how to make a pipe bomb has serious problems. The directions are in the name--get a pipe, make it into a bomb.
I dunno.
Maybe we better see the instructions he sold -- just to be sure.
"Anyone that can't figure out how to make a pipe bomb has serious problems."
The more serious problems arise in loosing your fingers after you have made it -- making a good fuse from scratch is not easy.