Continuous meter movement with all intentional use off is stronger evidence of a supply loss than a stain that appears after rain or bathing.
The highest-cost mistake is letting an approximate clue become an exact excavation point. Ask how supply branches were isolated, how the suspected line was traced, and what evidence supports repair at one location versus rerouting a section.
Keep this boundary: The phrase slab leak describes a location relationship, not a diagnosis, cause, or automatically preferred repair method.