I didn't use Hitler as a reference point for a political persona though. I used Hitler's popularity as an example of how it's rather weak to argue from the popularity of a leader.
And sure there are exceptions. From the Wikipedia page about Godwin's Law:
"Godwin's law applies especially to inappropriate, inordinate, or hyperbolic comparisons of other situations (or one's opponent) with Nazis – often referred to as "playing the Hitler card". The law and its corollaries would not apply to discussions covering known mainstays of Nazi Germany such as genocide, eugenics, or racial superiority, nor, more debatably, to a discussion of other totalitarian regimes or ideologies"
Also:
"Godwin's law itself can be abused as a distraction, diversion or even as censorship, fallaciously miscasting an opponent's argument as hyperbole when the comparisons made by the argument are actually appropriate."
The topic of the OP referred to protests against Putin's soft authoritarianism while the Hitler reference was not an inappropriate, inordinate, or hyperbolic comparison but instead just an example of how the popularity of leader is not a good way to judge them. It did not at all compare Putin to Hitler.
So yeah, arguably in this case invoking Godwin's Law was a fallacious miscasting of my argument. Not so much ab's mention of it, which I think was only half serious anyway, but definitely Putin33's later dismissal of what he deems 'so called' democrats (aka people who know there's more to democracy than voting).