A war room / call is for coordination. If you need the person draining the bad region to know that "oh that other region is bad, so we can't drain too fast" or "the metrics look better now".

For truly understanding an incident? Hell no. That requires heads down *focus*. I've made a habit of taking a few hours later in the day after incidents to calmly go through and try to write a correct timeline. It's amazing how broken peoples' perceptions of what was actually happening at the time are (including my own!). Being able to go through it calmly, alone provided tons of insights.

It's this type of analysis that leads to proper understanding and the right follow-ups rather than knee-jerk reactions.