Rather then actually fix the problem (say by requiring a 5 minute minimum time for placed orders) they simply make money on the traders and then when the market goes down find a scapegoat to arrest for doing what their system explicitly allowed.
A
two second minimum life-span for orders on all exchanges would be the simplest and most effective action regulators could take to stabilize markets. That UK trader should get a medal for highlighting how broken the HFT-abused markets are.
I thought the main problem was still naked short selling or orders that appear but are never completed. They cant really enforce times on orders due to a large industry of very computerised trades, legitimate and paid by the exchanges to provide liquidity. If they interfere with that it would reveal how low real trading volume has fallen since 2000 and cause all sorts of problems.
So they outlaw tricking computers which I think is basically what happened, I thought they'd already taken measures like the really basic one of suspending to an auction if the market moves too far too quickly. I think its happened since a few times that a major market has stopped mid day a couple times just not recently