Herb is a pretty good Ref. Big John is the best in the UFC in my opinion but even he has made some bad calls.
We must remember as viewers of an event on TV we get camera angles and mic sounds. We can't see through the eyes of the ref and we can't hear through his/her ears. Often when watching from our couch we get to see things like fence grabbing, illegal blows,..etc.. whilst the refs are focusing on something more important such as maybe the arm of the opponent in an arm bar or watching the hands for "tap-outs". In some cases these things are just not in view for the refs.
Like wise we don't always see what the refs see from the camera angles we are given. Take Roger Huerta last fight against John Halverson. From our view at home, given the camera angles, it looked like Huerta came in and kneed him in the head while he was down. (some of you with sharp eyes might have seen it in differently
) For me it took a couple of replays for me to start to notice that it was a shoulder hit and not a head shot.
Remember if you think these refs are bad I've seen way worse at local events. These guys are the best in the biz, that's why they are here. Bad calls will always abound. Whether it's the UFC, Pride, IFL...etc...
p.s. If you feel like calling out a ref as crappy, feel free to go get licensed and jump in the ring and try it. You might be surprized at how difficult it actually is.