You nailed Ed Lake. He likes to spread false information that it was all just a big misunderstanding with the media. Of course you are correct. There are dozens of named Federal officials who stated silica was used as an additive.
The Armed Forces Institute of Pathology (AFIP) published a Newsletter in October 2002 (1 year after the attcks) stating that silica was a key additive of the powder sent to yourself. They used a technique of SEM/EDX to determine this. The persons responsible for this work were Florabel Mullick, Frank Johnson, Victor Kalasinsky and Marie Jenkins. They relate this finding here: http://www.afip.org/images/public/nl081002.pdf
How many more years do you guys think are going to go by before Lake stops pissing on all of us and telling us that it's raining? His strained leaps of credulity become tougher for me to swallow all the time.