A fair review notices the decision that made the error easy to repeat.

Finding out who did it answers a much smaller question than it appears to. Most mistakes are made possible before they are made: an unclear instruction, a missing check, a schedule that guaranteed somebody would be rushing at four in the afternoon. Stopping at the person leaves all of that in place, which means the same error is available to the next person in the same seat. Blame feels conclusive and changes nothing.

After something goes wrong, ask what made this easy to do rather than who did it. Change one condition rather than issuing one warning. Then see whether the same thing happens again.