It seems to me that it would be quite difficult in many instances to prove whether a rod was broken due to defective materials or workmanship versus being caused by the owner. If the reel seat came unglued and fell off that might be more than likely due to a manufacturing defect, but who can determine with certainty what caused a rod blank to break?
I've broken a rod by pulling too hard on a snagged fly. Was that due to an error on my part or a defect in the materials? Well, that one might have been broken due to my mistake, but I'm not entirely sure.
I've also broken a rod when fighting a fish. In that case, I don't think I did anything wrong, but who could determine with certainty? Would rod manufacturer's have to state in their warranties that the rod is only warranted when bent only up to a specific degree? We know that a rod can only be bent so far until it breaks, but who would be there to determine if the rod broke by bending it too much when fighting a fish?
I have owned a lot of rods over the years, and have broken a lot of rods. I know for sure that I caused a number of the breakages, but I would defy anyone to know for sure what caused many of these rods to break.
My opinion, therefore, is that either rod warranties should be limited by time - unconditional for 5 years, for example, with perhaps a stipulated repair cost afterwards, or they should be unconditional for the lifetime of the original owner.
I just bought a new $800.00 fly rod. That's a hell of a lot of money. But it was sold with an unconditional warranty for as long as I own it, for a $50 repair cost. I probably paid $200.00 of the $800.00 for this warranty, so that's exactly what I expect to get should I break it sometime down the road.