He was paid by Google with money made through Google’s shady practices.
It’s like saying that it’s cool because you worked on some non-evil parts of a terrible company.
I don’t think it’s right to work for an unethical company and then complain about others being unethical. I mean, of course you can, but words are hollow.
Are those distributed systems valuable primarily to Google, or are they related to Kubernetes et cetera ?