Yeah Mike did not quit on the show. It is not him to quit. Check out this article from a while back. This is what kind of guy he is.
He went through the fight, lost a three round decision, and decided to visit a doctor the day after the bout. The conversation went something like this:
“What do you do for a living?” asked the doctor.
“I’m a professional fighter,” Whitehead replied.
“When was your last fight?”
“Did you pass out?”
“That’s amazing because there’s so much infection going through your veins right now that I don’t see how your veins are carrying oxygen to your brain along with all this infection.”UFC Interview about Whitehead