Did she make the change on company time? If so, her wages would be material damage. Even if made off the clock, it could still be considered material because Google needs to pay someone to fix it.

Your voting/property analogy is completely off-base. It completely ignores right of ways and public property. And if you have people actually trespassing on private property on the way to a polling place then they are in violation of the law and can be cited. I see no legal way that you can "weaponize" property law to prevent access to a polling location. Also, there's nothing stopping employees from exercising their right to concerted efforts off company time and property.

I think the far more substantial damage is from Google customers wondering what else the employee or some malicious insider could have done. You can bet that this came up in internal audits and customers' security assessments.