Interesting information. I had a gentleman at REI explain something very similar to about hiking boots and outdoor clothing. Had a Columbia jacket that was tagged 100% "waterproof". Found out the hard way it wasn't. Companies can claim things are "waterproof" by the permeation time of water. That being said. My jacket was waterproof for a couple of minutes then the permeation started....It was waterproof, just not for long. If an article of clothing is tested and is there is no permeation for a few seconds, well it's "waterproof"....LOL. Leeson learned....Do your research and read multiple reviews!!! Nothing worse than ruining a piece of expensive electronics or getting caught in a downpour and getting soaked....
Yup companies like to use the word waterproof to the average consumer implies stay dry, no matter what. Just isn't so. There are different requirements for enclosures (boxes) and clothes. You get what you pay for. I always bought Gortex, always kept me dry in downpours while fishing and warm