In reply to martinturner:
> Can that not be construed as wear and tear?
No.
An inadequately sewn seam is an inadequately sewn seam (i.e. the seam was not sewn as per the manufacturing specification).
A faulty fabric is a faulty fabric; again, not as per the manufacturing specification.
Fitness for purpose is a different matter. If you buy an ultralight running pack, and use it as haul sack up some granite face, don't expect them to honour a guarantee; that will be wear and tear, and not a failure of either the fabric selection during design or manufacture.
I think it's a pretty reasonably-worded guarantee. If you don't like it, don't buy their products.
Before you ask; no, I have no connection with Lowe Alpine...