It's a single cam brake and that cam will apply brake if you pull on or push on the actuator arm, and I'd be very disappointed if you track guys can't see why his rear brake is NON-functional. Did you never have to reposition foot controls on a drum brake bike that had a steel rod for an actuator arm?
The brake actuator rod needs to follow a similar arc to the swingarm travel, or he needs to float the rear brake so everything follows the same arc of travel, or he needs to replace the solid rod brake actuator with a cable system, or he could replace the rear shocks with solid struts so the rear wheel no longer moves up and down. Anything short of that and a rider will be in great danger.
If a mechanic safety certified that setup, they should lose their license.