i would suspect that the warranty would only cover holes where the waterproof backing layer has delaminated (i.e. manufacturaing defect/meterial defect), rather than puncture holes which would be down to how the item is used. Stick it in a bath - clouds of bubbles from an area indicates delamination, a stream of bubbles from a single location indicates a puncture hole. A quality seam sealant applied on the outside can plug small holes, patches will be needed to plug bigger ones.