I think there is a little bit of a difference between Condit KOing Hardy and Alves subbing B.J. First off, I have always been of the opinion Hardy is very overrated and to this day don't understand his title shot. Secondly, there is a much better chance of a fighter landing a KO shot than subbing a BJJ black belt.
I don't think Condit got lucky with landing his shot but a lot of other fighters who KO their opponent do get lucky. Getting a top level BJJ guy in a triangle is going to take a hell of a lot more skill than that. You may see someone fall into a triangle but usually not a black belt.
Also, I don't know if it was intentional but comparing Hardy's standup to B.J.'s ground game is kind of funny.