The guy gets stopped for a driving violation. He knows he has $800k in the vehicle. He eventually lets the cop search it, maybe hoping the guy is stupid. He’s not, and he finds the cash. They arrest Armstrong and say the money smells like weed.
What was the crime? Having a lot of smelly money? There certainly is more to this story than was reported.
A traffic stop isn’t always just a traffic stop. Could be he was under surveillance prior to the stop and the police already knew he was carrying the cash. Had he not granted consent the dog would have detected marijuana smelling cash right away.