I think the title refers to the Knight Capital Group incident which is referred-to in the Editor's note:

  One of the most interesting things about the catastrophe
  at Knight Capital Group—the trading firm that lost $440
  million this week—is the speed of the collapse.

I didn't realize the market crashed as a result of the Knight Capital incident. Hmm, let me go look at a stock chart:

http://www.google.com/finance?q=INDEXSP%3A.INX

I see a few 10-20 point losses at various times in the past month, but nothing that looks like a crash.

I'm disappointed by your lack of outrage, comrade.

Perhaps it refers to the crash of Knight's own stock price. I do vaguely remember a FT headline that day (Wednesday) about market prices falling due to the problem.

Yeah, "the" crash means Knight's fail.

The headline made me think is was the 2008 crash - caused by the same issues...

It appears this article was written and slated for a September publication before the Knight incident. While the Knight incident is mentioned in the leading editor's note, the crash most prominently dicussed in the article is the May 2010 'flash crash'. The title as submitted is vague and misleading.

I remember that. I was working in HFT at the time, so I certainly noticed when it happened.

But I decided to try an exercise. I went to google finance and graphed the S&P. From the graph (weekly data points) I can't tell when the flash crash occurred.

It's almost as if the flash "crash" was just a flash in the pan...