The action you link to was not perpetuated by HFT. The vast majority of Lightspeed's business is good ole fashioned screen traders, and that is likely what this was. Previous actions for spoofing and layering were also the result of manual traders using regular day trading tools.
My mistake. I assumed HFT was involved because the timescale of the "layering" orders and subsequent cancellation (following the bona fide order execution) was on the order of several hundred milliseconds.
