Then you probably can claim that Linux is written partly in bourne shell.
The kernel devs don't do development on master! However, git's fast-forward-merge will, by default, push development/intermediate commits onto master. Those intermediate commits are extremely useful for code-inspection/code-review and bisect-based debugging. They're are not meant for starting a new dev branch and that why they're not tagged! There's nothing new or interesting in that article other than a bunch stupid comments at the bottom. The whole thing smells like a disguised advertising for PlasticSCM
Research is what I'm doing when I don't know what I'm doing. -- Wernher von Braun