Is it not possible -- even probably -- that Google had a legitimate legal claim on the work?
Aside from the argument re whether it is morally right, it's not uncommon for software companies to assert ownership over the intellectual output of their employees, whether the creative process takes place on or off the clock.
Joel explains it better than I can:
* https://www.joelonsoftware.com/2016/12/09/developers-side-pr...