Binance caused this by both announcing and driving a run (by selling a tonne) of FTT right?

You would only do BOTH if you were actively trying to kill FTX. If you wanted to protect your investment/capital, you would QUIETLY sell your FTT. If you wanted to alert the public, you would announce your concerns. Doing both is no different to how 1700s or 1800s banks intentionally drove runs in each other to kill competition and drive up their own business as far as I can tell...