First preserve all documents in their original form. This includes the policy and terms, emails, messages, photographs, invoices, medical records, notes of conversations and letters from the other side. Record the sending or receipt date of every important message.
Then make a table with date, event, knowledge, notice, reaction and affected loss item. Mark when the loss was recognised and when the responsible person became known. Add whether the insurer or other side had learned of the event by another route.
Separate the legal review into three results: What can still be proved? What specific contribution is alleged? Which period may be running? These questions belong together, but they cannot be answered by one broad conclusion.
If a deadline is approaching, obtain a prompt assessment of the legal bases and the correct claim route. A late report remains useful, but it does not replace the legal assessment of limitation and possible steps to preserve the claim.