Speaking out about legal violations is not only allowed, it's protected by whistleblowing laws. It's an adversarial process, but legally protected.

What Google frowns upon, and will terminate an employee legally for, is speculation outside of that legally-protected space. So going to the SEC with evidence Google is acting bad? Legally protected. Circulating in an email "hey, is thing X that team Y is doing monopolistic?" No, and you'll get canned for having that discussion in an unprivileged environment without legal counsel present.