Possible Reason #1: He does not read newspapers or blogs or watch television.
Possible Reason #2: He actually had heard about it, but as a lawyer he was shocked and horrified that a fellow member of that profession could do such a thing, and he repressed the memory.
Possible Reason #3: Every weekday he showers, gets dressed, and leaves the house to go sit under a rock for eight hours with his hands over his ears yelling “La la la la!” really loud if anyone tries to tell him what’s going on in the world.
(Just google “pants lawsuit” if you don’t know.)