The point of Postmortems (or post-incident reviews, since dead bodies are not relevant here) is to learn as much as possible about what happened before, during, and after an incident. The result: everybody has the same shared knowledge. But don’t assign blame. Blame discourages people from sharing what really happened.
VictorOps, a tool for incident management, offers a feature for powerful postmortems, in which you can review a timeline of all activity related to an incident, add notes and observations, and share action steps to take in the future.