Is there ever a reason to fuse the neutral rather then the hot line in a small appliance?
If your wiring analysis is correct and the neutral is fused, this is most certainly atypical. The hot is fused to prevent a ground short from burning out the appliance and is the reason that a grounded neutral or reverse-polarized electrical plug can be dangerous. Fusing the neutral would not prevent this, which is exactly why the breaker tripped instead of the fuse blowing.

As for why it was done this way? Beats me, unless it is an error. Have you considered contacting the manufacturer? It may simply be an oversight in the U.S. wired models.