 Your experience does not give you justification to believe that the lines are different in length once you have gain the evidence they are the same in length. Such cases are ones of “defeat”, where further evidence opposes or otherwise disrupts your receipt of justification from your experience (some cases may be like someone writing over the graffiti drawn by experience, other cases may be like someone erasing the graffiti drawn by experience, and perhaps there are further variants of defeat as well). To take account of such cases, the fan of Sufficiency can say that