Considering that everybody was seeing Khan on a stretcher, I don't think he lost anything, even considering, which I believe is true, that Barrera has a leaking tank after all these hard fought fights over the years. Khan did beat him fairly in every rounds with his speed, which show that the guy sure has at least a fair bit of talent. I agree though that the fight should have been stopped before the fifth and that it was a kind of cooked manoeuvre to give him a win instead of a no contest. Indeed, he looked good, sharp and strong, that's what they needed to coat a layer of golden over his tarnished image after the Prescott's slaughter. They needed to show that he has skills and could perform against much tougher and meaner opponents than Prescott and that's exactly what they got into the 5 rounds of fight against Barrera, the fight should have been stopped before but the kid performed well and showed what he had to winning every rounds without question.