Finding
The installer may carry account knowledge, exact commands, recovery steps and component relationships in their head. Their demonstration can unknowingly test a different pathway from the one the intended operator must use.
How the mechanism works
Invisible expert knowledge temporarily completes missing transitions. Once the installer leaves, the system loses those transitions and the intended operator encounters the actual pathway.
Evidence boundary
Assistance is not inherently a failure. The relevant distinction is between chosen support and unplanned dependence.