I don't think he was gassed. Looking at him in between rounds, I personally saw no breathing issues. In that respect, I think he was fine.
This is how I see it. Anderson keeps referring to being disrespected by Maia. For the first few rounds, Anderson was doing his thing: landing shots, juking and jiving, ducking and moving, punching and kicking, showboating and taunting. Maia was clearly not game for Anderson, thus he (Maia) refused to fight or engage. I think Anderson felt disrespected by this, not only by Maia but all other fighters who do it, so I think he tried to prove a point. He basically stopped fighting, was unwilling to engage even when Maia rushed in, or play into Maia's game, thus showing how disrespectful and frustrating it is to be Anderson and not have a #1 contender willing to fight him. I honestly think he tried to prove a point by doing all of this.
Maybe I'm wrong, I don't know, but that's what I think. Don't take that as me excusing it, because I don't. I'm simply trying to make sense of a crappy and curious situation.