I just watched this fight earlier today for the 1st time. It was a good fight. Both were landing and hurting each other but I thought Mcclellan was leading in the fight. And ended with Mcclellan quitting?

I can saw that he was a little dizzy and was basically blinking like he was trying to get his senses back while the ref was counting him out. I thought that he could have continued. However he didnt. What was that all about? Why in the world did Mcclellan quit? What happened to him ? What happened to Nigel Ben?