From the wedding‑dress shop and France Télécom examples, several investigation points stand out:

Patterns, not just incidents. Investigations must look at repeated behaviours and overall management methods (pressure, insults, humiliation, unrealistic targets), not just isolated events.

Impact on working conditions. The legal test is about degradation of working conditions and impact on health, dignity, and career, so the investigation should explicitly document those effects (stress, health problems, resignations, deterioration in atmosphere).

Multiple testimonies. In the 2025 case, the internal investigation report was key because it contained consistent testimonies from several employees, including the claimant herself, confirming both general practices and their personal impact.

Link to dismissal (or not). HR must investigate not only whether harassment occurred, but also whether the dismissal or other measures are directly linked to that harassment, because that determines whether termination can be declared null or just give rise to damages.

Respect for medical confidentiality. The employer contacting the GP without consent was a separate investigation issue, leading to nullity of dismissal; HR must be very careful about how health information is gathered.