The figure was wrong by a single digit. Apprentice Tavi noticed it when checking the late surveyor's notebook against the companion sheet. She feared that correcting it would look like criticism in an archive prepared for his memorial.
The companion sheet preserved the arithmetic, and a second observer's entry supported the corrected value. Tavi added a dated note explaining the discrepancy, leaving the original number visible. The error was narrow; it did not justify dismissing the rest of the man's work.
His former colleague thanked her. The surveyor had insisted that a useful record make correction possible. Treating his notebook as untouchable would have honored him less faithfully than checking it with the same care he expected while alive.
At the memorial, the open page showed the mistaken digit, the supporting sources and Tavi's annotation. Visitors could see work continuing rather than a reputation being damaged. The final measurement was no longer the last word, and the notebook remained valuable precisely because another person could inspect it, disagree in a specific way and show how she reached the correction.