I suppose it depends on circumstance Like if a fighter loses to an unknown at the time who then goes on to secure a few more notable wins the loss doesnt seem as bad In all its damage control but nothing to brag about I guess
It depends on how much the winner accomplishes. The logic goes that its better to loss to a great fighter than a fighter who isn't great. So, the greater a fighter is, the less a loss hurts the legacy of a fighter who loses to the great fighter. Tito Trinidad's embarrassing loss to Hopkins was put in perspective after B-Hop went on to outclass plenty of other outstanding fighters. Similarly, Antonio Cervantes' violent loss to Aaron Pryor is retrospectively mitigated by the reign of terror after lifting the title.
It doesn't matter enough to make a big difference, but if he loses to a great fighter like Vladimir Klitschko it will not harm his record that much............after all, who beats Klitschko today?
There are some clear examples. One of my (very few) countrymen who made some waves in boxing lost a SD in his second comeback fight to a 13-7-2 journeyman called Orlando Salido. Now that doesn't look as bad anymore