possibly the operator could define 'crew' themselves seeing as it's so vague.
eg an airline can define crew or non-operating crew for a gen-dec.
so if its ariel work can't the radio guy be classified as 'non operating crew essential to the primary task' (news reporting). that way you've made an attempt to address the pronlme and the worst case is the CAA saying...nice try, don't do it again.
better still why not get a lawyer to make a written arguement to them for a derrogation for that particular operation..
FS