The argument wasn't that he hadn't done anything wrong, it was that he was not informed what he had done wrong. He admitted to violating the ToS.
If you want to optimize for justice, there are plenty of failures in Google and Google's ad programs. They seem to be pretty clear about their intention of optimizing for profit, though.
The same para-legal would have sufficed with better preparation -- finding out the reasoning for account termination (i.e., non-content domain).
It was the difference between their right to terminate for no reason and any reason.