At smaller venues, fighters records are whatever they say.
CB is 9 and 2 according to wikipedia and Sherdog.
Gray Maynard is undefeated because his fight with Emerson in the TUF finale was a No Contest. He slammed Emerson and the ref stopped the fight. From WIkipedia:
"At the The Ultimate Fighter 5 Finale, Maynard fought Rob Emerson in a controversial fight. Maynard seemed to be in control of the fight in round one. During the second round he picked up Emerson and slammed him to the mat. Emerson immediately tapped out because of an injury to his ribs. The referee claimed that Maynard also could not continue because he seemed to have hit his head on the mat and knocked himself out due to the force of his own slam, thus because both fighters could not continue he ruled it a "No Contest". UFC President Dana White commented, "I know one thing, that Maynard was out cold". Maynard did not agree claiming that, because the ring-side doctors found he suffered no concussion during the bout, he had never lost consciousness in the fight."
Matt Serra on Wikipedia is 15 and 6 and on Sherdog he is 9 and 6...but below his list of fights on Wikipedia it states - Note: His record does not include his two wins while on the Ultimate Fighter as they are classified as exhibition bouts.....it only shows the 9 fights.