A better firearms-related analogy would be your custom revolver blows up in your face, rendering you blind. The gunsmith has insufficient insurance or assets to pay for your injuries. Your lawyer, seeking only to make you whole, also sues Pine Tree Castings, a supplier to the revolver maker, to add them as a potential deep pocket. If your lawyer can establish that Pine Tree Castings was negligent in the design of the part or shipped a defective part, you can collect on that. The concept of moving up and down the supply chain looking for potential defendants in product liability or personal injury lawsuits caused by an object is not new.
Edited to add: I almost forgot, it was so long ago. But when I first started working for the lawfirm back in the 80's, they were the lead Washington state defense counsel for the asbestos mesothelioma cases. There were many such cases in Washington, and almost all of them were men who worked in the Puget Sound shipyards around the WWII era and were exposed to asbestos lagging/insulation products on board civilian and Naval vessels. Everyone from the asbestos mines, to the processors, to the distributors, to the lagging/insulation companies and other companies in the supply chain were defendants in those cases. I never really worked on those cases but I did do some legal and medical research on the issue of smoking and mesothelioma. It turns out that smoking and asbestos exposure increases your chance of developing mesothelioma. And almost all the plaintiffs were middle-aged to elderly men who all smoked like chimneys, including while they were working with asbestos products. So trying to figure out how did your smoking contribute to your mesothelioma was a big part of those cases.