Seen him live and, if anything, his action looks worse in 3D.
Murali's action has always looked bad in 3 D.
A little story: even as a school boy cricketer when he was picking up swags of wickets every season, his action was a source of doubt. I can still remember reading an interview with Bruce Yardley way back in 1989, when he had arrived in Sri Lanka to do a spinners coaching clinic, where one of the first questions he had to field was the legality of Mural's action. His opinion at the time, iirc, was that while initially doubtful, he did not - after extensive work with Murali - think it illegal anymore.
I don't doubt that he can bowl within the legal limits, but equally I'm sceptical as to whether he always does. His action sometimes looks worse than others and, if there really was no advantage to be gained by increasing elbow flexion, the more cynically minded might wonder why then his action does appear to deteriorate?
I think there is some truth to this. Certainly at times, especially at the end of long spells, his action has looked less fluid and more ragged - often, for example, where he tends to go searching for something extra, and in doing so may contravene the rules. IIRC a few years ago this was picked up, that due to extensive bowling and a heavy test schedule his bowling action had begun to deteriorate, and he went away and worked on his action and came back a better bowler. However, I dont think Murali is alone in this. Other bowlers also tend to find their actions deteriorating or contravening the rules - especially when searching for something extra. But the fact that scrutiny is pervasive over Murali means that these instances are picked up and worried over more than most other bowlers.
Frankly, I dont think Murali chucks his offie or his toppie. Neither do I believe in the hypocritical sanctity of patently faulty and false rules - despite the wailing and gnashing of teeth by the 'old boys brigade'. I do, however, as I have voiced many times, have reservations as to his doosra. And certainly, for a while there (mid 2000s), I thought it made him a worse bowler despite his increased penetration at test and odi level. His doosra is, imo, better than it used to be (he seems to have done some work on it) but it is still a cause for concern - especially at the end of long spells and/or the end of a heavy season. Frankly, I am often in two minds about the latter issue.