No, it was since Spain or Monaco. However the FIA originally said it was legal but after appeals from other teams, it was deemed illegal./quote]Wrong. They ask Charlie Whiting if it's ok with the rules. Charlie said, that in his opinion it is ok.
However if it comes to a protest (or a demand of clarification like here) his first opinion is not worht much. It is down to him and other people to look at the diffrent interpretations of the teams and to specifiy which is legal and which not.
In 2009 we had a similar story with the double diffusor. Charlie said in winter to Brawn that it is ok with the rules. However the other teams had diffrent opinions and protest against the race result (which now no one did). Afterwards the double diffusor was specifed as legal by a comitee or something similar.