This just doesn't look like the guy who would leak thousands of emails to Assange. If he were, and had access to DNC files, wouldn't he have passed on more damaging information?
But Binney left the agency in 2001 and has been regarded by it as an enemy since the Bush administration, so would he have any accurate knowledge of what was going on there years after he left?
He was a Bernie bro. Was upset they fixed the nomination. Wanted it exposed. Clear motive, opportunity, and means.
He likely naively believed Hillary would bow out in favor of Bernie.