Large corporations like Google have a lot of resources and connections to really mess up a single persons life if they really want to, with expensive legal action and PR campaigns.
Yeah, they might cause their reputation some damage by going after the wrong person, but let's be real here.. the worst outcome for Google would likely be miles ahead of the worst outcome for Hinton.
Edit: Note that I'm not actually saying that I think Google and Hinton have this level of adversarial relationship.
I'm just saying that big companies may come after you for speaking out against them regardless of if you've accepted hush money or not.
Given that, it's usually worth
being tactful when talking about former employers regardless of any payouts you may have accepted or agreements you may have signed.