He got hit with a big knee to solar plexius and gave Anderson a smile after and proceeded to start running, but regardless of if he was hurt of not there are other factor in a fight that could cause a fighter to want a break in the action, maybe he was tired? Maybe he didn't like the fact that Anderson had him backed up against the fence and wanted a break and a opportunity to get out of that position
When someone spits out their piece it causes a break, the ref separates the fighters, washes the mouth piece off and then squares them back up and yells "fight", knowing this, fighters have spit them out on purpose to get a break, it's an old trick that refs don't fall for anymore, Bisping got desperate and despite being yelled at multiple times by the ref to "keep fighting" he tried to force a break when he was hurt, tired or not happy with his position
So if a fighter is hurt you support letting them off the hook if they lose their mouthpiece, gotcha
Anderson followed the refs instruction and if Bisping was able to complete a sentence as you say, it should have been ample time to for him to hear and process the same information.
Pressuring for a short time and doing damage > Pressuring the majority of the time and only landing pitter patter.
When the ref is screaming at you to "keep fighting" that's what you do, Bisping isn't the ref and doesn't dictate when they stop unless he wants the fight to stop entirely....End of discussion.