[kasey_junk]

That's not what the article says. It said that trades occurred at the crashed price (and that's the common definition of 'price' when covering trades)

[jstanley]

He means the resting asks did not drop that low, only the resting bids.

[kasey_junk]

The resting visible asks.

Clearly if the exchange matching engine was working properly there were asks that low (in the form of stops).

That's pretty typical in crashes.