Looks like what they're calling 'false claims' is extremely narrow and based on simple objective facts:
> For example, Google would remove ads that falsely claimed that a candidate had died or that gave the wrong date for an election.
> However, it would not ban claims that you cannot trust a rival party, for instance, which would be viewed as being a matter of opinion.
IMO, I think the better approach to handle truthiness issues is to give the other party/candidate/candidates a chance to post a rebuttal.