That being said, if you don't audit your open source libraries, you should be held liable. I've seen open source encryption libraries do some really dumb things that I wouldn't touch with a ten foot pole. Yet they are some of the more popular ones.
/e: let me clarify, I agree with the three comments under me. You, the commercial entity using my code, is accountable. I am not liable if you as a private person run my shitty code. I was thinking of private persons and being on the hook for my GitHub repos.
This over the top article is, I guess, pointing to open source software that's used by an individual directly from the source as an enduser and then causes harm, not to parts of commercial software that includes open source software when they talk about holding open source devs liable.
Basically they can't just brush off responsibility for using FOSS code by saying "well I didn't write it, it's not my fault" unless you as the FOSS developer are selling them a support contract for any potential issues in your code.