Hendricks has been in the last 3 welterweight title fights. All of them have gone to decision and all of them probably could have gone the other way justifiably.
His loss to GPS was close, his win over Lawler the first time was close, and his loss to Lawler tonight was close.
When Hendricks won the vacant title, he probably won it at the end with that 5th round takedown against the cage where Lawler couldn't do anything but look at the clock. What happened in the 5th round this time? Lawler was unloading and landing shots.
Lawler wasn't trying for any take downs (per normal) and Hendricks did. But Lawler stuffed more than half of those take downs. And when Hendricks got the takedown, he wasn't doing much with it but lay and pray and some wall and stall. Maybe the judges are starting to get wise to that? I don't know.
Moral of the story: As they say, "Never leave it in the hands of the judges."