The fumed silica (Cab-O-Sil) was, but remember, any formulations chemist worth a crap who was familiar with aerisolizing an active would have known to use it. That technology is increasingly common as the drug delivery industry moves toward getting rid of needles (fear of HIV liability associated with needle-sticks of doctors and nurses). That's why patches and inhalants are so common these days.
The biologists who understand handling anthrax probably don't qualify to aerosolize it. It therefore means NOTHING that the FBI guys weren't able to replicate the Senate anthrax without an analysis of the project, its personnel, and its available tools. It could just be another stupid government SNAFU.