I'm unconvinced that Murali's action (where to me his arm remains somewhat bent all the time) is giving him an advantage. His flexible wrists seem to be the biggest factor on the amount of turn he gets, to me. And he still has to put it on the spot, vary his flight etc. Try "throwing" down some offies in the nets. Generally they turn less in my experience, and are a nightmare to bowl accurately.
As for a "disability" (or more accurately, different from the average human ability) giving a player an advantage, where do you draw the line? Does Sobers' outrageously quick reflexes and hand -eye co-ordination count? I guess you can argue that Sobers' "extra - abilities" were within the laws, but I'm convinced that Murali's are also.
I've done a complete turnaround on this, btw, for years I considered him a chucker and a cheat, till I took the time to really study his action. Great bowler, good luck to him.
Hair and any other umpire won't call him again. To big a can of worms. The ICC has cleared his action, end of story.