In this context, I don't think the distinction matters.
If I was choosing ingredients for a brownie to sell, using THC would restrict which US residents can buy my brownies. Is it the fault of the lawmakers in my customer's state? Or is it my fault for choosing an ingredient that's banned in most US states? If I'm trying to maximize sales, the question of blame is irrelevant.
From a practical standpoint, it doesn't matter whose "fault" it is that a Googler can't contribute to an AGPL project. Choosing an AGPL or similar license prevents me from receiving contributions from people who otherwise might be interested in contributing.
But from my perspective, I'm fed up enough with Google's anti-AGPL FUD that I don't mind not getting contributions from Googlers for a while. It's gotten worse than Microsoft in the nineties.
And with critical mass, Google will hopefully make a similar turn. Microsoft is now the world's largest open source contributor by some metrics. I don't know if I buy those metrics, but it's big. Same thing will happen to Google, hopefully.
Unquestionably, yes. They know exactly what kind of business they were looking to restrict with those laws, and in your analogy they stuck all the fallout from that on you. (That's not to say one shouldn't be civic-minded, but for the record I tend to avoid analogies when talking about this because they more often seem to confuse the issue than actually explain what is happening)
In that case Google's policy is what is restricting you, not the license. The AGPL doesn't say you can't contribute if you work for Google. I'm sure AGPL users (like the company in TFA) wouldn't mind if Google reversed their policy and gave their employees permission to contribute.