That would be the way I’d argue it anyway. “Sure there was horrible stuff on that drive, but that doesn’t mean my client put it there.”
If I’m reading the story right they didn’t convict him just for what was on the USB, that was used to get a warrant to search his home and then he got convicted for stuff found there and on the USB.
Sounds like a lawyer who was more interested in making his bones in a flashy first amendment case rather than defending his client.