The summary made it sound like a domain registrar just transferred the name without their permission, but that totally is not the case according to the article:
In the past, the domain "nagios-plugins.org" pointed to a server maintained by us, the Nagios Plugins Development Team. The domain itself had been transferred to Nagios Enterprises a few years ago, but we had an agreement that the project would continue to be independently run by the actual plugin maintainers.
So really the company just decided they want control of the server now instead of pointing their domain to a third party. Nonstory.