I guarantee they wouldn’t shut down the line while they wait for a fix for within-tolerance panel gap improvements - they would work on designing a fix that would be implementable on the line while continuing manufacture. Designing, Testing and Commissioning an improvement will often take many months.
The zero defect thing is fixing issues early rather than fixing them at the end - not shutting down the whole line if you identify that a tolerance can be improved and waiting for the fix.
