It's possible, although everything seems to point to it being an individual so far.
Even so, it would take more than Briatore knowing of the whole thing for him to be guilty. It could be that Briatore said no, don't do it. Or that he just didn't take the suggestion seriously. Either are
plausible (I'm not saying probable) given Flavio's reactions. E.g. "he's not a f******g driver". For Flavio to be guilty, he'd at least have to have known of the plan, known that it was going into effect, and supported or at least implicitly allowed the plan. For all we know, Flavio might have said something like "don't be ******* silly" and ignored the suggestion after that, only to see it come to fruition.
If it is an individual, could it be Nelson Piquet senior?