I disagree with the example. If I recall the scene, the speaker was complaining about the FBI's browbeating him into "consenting" to a blood sample. In that case, "fascist" is more accurate to the attitude and has little if anything to do with dodging Godwin's Law.

The law in general seems almost unnecessary, to boot. If I follow its intent, then the idea is that if someone says "fascist" instead of "Nazi," it should be treated as if they'd said "Nazi"? In my experience "Nazi" will get said shortly thereafter anyway.

And don't forget that, in its original formulation, there's nothing to "invoke" about Godwin's Law. It merely states that the longer the discussion goes on, the more likely someone will make a comparison to Nazis. Once "fascist" or "Stalinist" or "Communist" or some other undesirable hits the table, "Nazi" isn't far behind.