Our Canadian friends appear to be a lot more forgiving of "boys experimentation" than we would be in Australia.
If a pipe bomb was found in your luggage here, I can assure you the following will happen, VERY rapidly.
You assume that the Security Artist identifies the object as an explosive device... If I make two pipe bombs connected by two meters of fuse and the guy at the X-ray scanner identifies it as a jumping cord.
At least it seems like some misidentification of the device happened initially in Canada, it's pretty hard to look into a sealed metal tube and find out whether it's filled with innocent plastic or more explosive material.
The guy got his grilling on return.