Fisbhed,
yes, unfortunately it is very much a weakest link scenario. However, good ATC might in many cases be the safety barrier taking a bit of load off the weakest link. Good point about the first step. In the future, I for one hope that all involved entities will have an appointed Quality Manager/Quality Management Dept who/which is a separate entity and NOT under the control of the management handling commercial considerations in flight/line operations.
Cheers,
/ft