In no case shall the liens given by this chapter be affected by any inaccuracy in the particulars of the lien statement; but, as against all persons except the owner of the property, the lien claimant shall be concluded by the dates therein given, showing the first and last items of the claimant’s account. In no case shall a lien exist for a greater amount than the sum claimed in the lien statement, nor for any amount, if it be made to appear that the claimant has knowingly demanded in the statement more than is justly due.