All discrepancies in measurement should be carefully verified with the object of placing each difference there it properly belongs. Whenever it is possible to do so, the manifest errors in measurement are removed from the general average difference and placed where the blunder was made. An example of this rule is witnessed by corrections for chaining errors.
When it is obvious or unquestionably proven that the original surveyor made a tally blunder in his chaining, the amount of the blunder is corrected before any remaining discrepancies between the retracement and original survey are adjusted or proportioned.
By placing any blunder where it occurred and weighing corroborative collateral evidence, the surveyor can make a professional decision as to whether a line tree or a blazed line is the best available evidence of the position of the original boundary line.