We use a lot of FOSS in our company. We pay licenses and contribute very little (our job isn't to improve gitlab or docker, we are shipping a software product on top of that), but I wouldn't know where exactly we are in the legal-illegal spectrum to save my life.
I consider myself an employee, not an entrepreneur. If I was an entrepreneur, I sure would happily seek legal advice on what exactly is fair use of open source. But really, I wouldn't know who to trust on the free advice market to figure out what I'm allowed and not allowed to do when starting up. I have absolutely 0 interest in legal stuff and it's mostly scary and confusing to me (and that's probably why I don't do any entrepreneurship, not even a side hustle in consulting), and I wish I and other salary men would be given a break about what the company is doing.
Nutanix shouldn't do what they are doing, but I don't think engineers should be to blame. At the end of the day, if an employee would have to go through everything that the company might not do perfectly right before deciding on a job, we would work nowhere. I wouldn't work for Oracle, but where to draw the line exactly ?