I think you'll find warranties clearly state "defects in materials or workmanship". They are not insurance policies. As to the unfortunate OP, these things happen. They always have, and they always will. They used to result in a scratch or insignificant ding, but with CF, all bets are off. I've stated many times that CF can't take these kinds of minor insults that any other material normally used in bike making would laugh at. It just sucks for the OP that he gets to be the one to prove it.

As far as a manufacturing flaw, get real. If the frame weighed more because it was designed to survive all foreseeable "minor" impacts without damage, nobody would buy it! CF is strong in certain directions but weak in others. It is ironic that many are afraid of steel because they think it will rust, but my bet is this sort of accidental damage has claimed more CF bikes than rust has steel bikes in the last 10 years. Unfortunate, but part of the compromise. Ultralight almost always equals ultrafragile.

FWIW, you can generally get a full replacement coverage rider on your home/renters insurance for your bikes for a couple of bucks a month....