Keep emails, messages and letters in their original form. For telephone calls, record the date, participants and key statements promptly. A chronology should distinguish direct observations, information provided by the customer and assumptions. Screenshots can help, but they do not always replace the original message and its metadata.
Review the affected contracts as well, without treating them as an automatic solution under unfair competition law. The contractual position can establish whether and which obligation existed. The separate question of whether the competitor acted unfairly under section 1 UWG still depends on the specific competitive conduct.
Public accusations are rarely a sound first response. They can escalate the dispute and create additional risks. Objective evidence preservation instead allows a focused out-of-court enquiry, an assessment of injunctive relief or the conclusion that no further action is appropriate.