We should stop nitpicking of which part of Bose QC-35 II headphones malfunctioned and caused the product to be deadly dangerous. Instead, we should focus on the following problems:
* How do we incentivize the manufactures to take safety of their products seriously?
* How do we make sure the manufacturers don't skirt the responsibility of selling unsafe products as safe ones?
One doesn't get enter the free market without agreeing to some rules first. The rules are what differentiates a market from a scam.
Actually delivering the product for which the money was paid is one such rule.
Clearly warning about lethal dangers of the stuff you try to sell is another.
Violations of either rule come with a cost - because these violations damage not only the customer, but the entire free market.