Following your postmortem, expand on your ‘lessons learned’ in a 1-2 page document. In the original scenario, you were alerted to the outage by your stakeholders.
What steps could have been taken to avoid taking down the DHCP server?
Furthermore, with a network monitoring system (such as Splunk), describe you could have gotten ahead of the outage and reassured the stakeholders before they came to you in a panic.