We're just speculating how much data would have been lost but one option would be to tell the owner of the data "hey you commented on pull request foo with comm

We're just speculating how much data would have been lost but one option would be to tell the owner of the data "hey you commented on pull request foo with comment 'baz' but we were unable to save it. Please comment again if necessary." It's not a great UX but neither is 24 hours of downtime.