Assuming for the moment that someone can see an execution from NYSE and route an order to NASDAQ in response in less time than NYSE can send their own order to that Exchange you haven't answered the rest of the question.
How does the HFT even know there is an order in-flight to NASDAQ? How does the HFT know that the buyer is willing to pay $10.02?
> You placed an ordinary 200,000 share limit order. You didn't use one of the special order types.
Is this supposed to be an answer? 100k executed at NYSE @ $10.00, this is public information. NYSE routed the other 100k to NASDAQ. Are you saying there is some way for Mr. HFT to know the particulars of that order to NASDAQ?
> knowing they can sell back to you when you buy the other half of your order.
You seem to be under the impression that at some point along the line someone besides the NUSE is seeing the parent order details (buy 200k @ $10.02). Please explain how you believe this information is transmitted to third parties.