Or, put another way, in lab conditions his action was illegal, so they changed the rules.
Yes, because it was discovered that as the laws stood, just about every bowler had an illegal action.
And then out on the pitch it became politically unacceptable to no ball him.
What the hell is that meant to mean? You think Sri Lanka runs world cricket? SL has one representative on the ICC board so it scarcely has undue influence.
And there have been plenty of bowlers forced out test cricket because of their action: I can think of Geoff Griffin, Ian Meckiff and Dusty Rhodes in my lifetime. Not to mention our very own James Kirtley - so the idea that test match umpires would be wary about no-balling someone for throwing is very wide of the mark.