<<And I think you may find a few pilots who might point out that as they're responsible for the aircraft they might be inclined to double-check what ATC or anyone else does rather than assume it's OK. >>
I can recall only one instance of a pilot querying my decision - and that was on radar where he thought a strobe light was a bit close and it was over 10nm away! At busy units there wouldn't be the available R/T time for pilots to double-check instructions.