I think it's combo of things. Here is my timeline of what happened.
1) A big player decides $265 is a good time to cash out. They decide to drop a couple thousands btc on the market all at once.
2) The epic price rise slows, then stops and stabilizes as demand can't eat through the thousands of coins as quickly as it normally can.
3) The "DDoS bandits" see that now is the right time for another DDoS snatch and grab.
4) As the DDoS brings many of the major exchanges to a near halt people begin to panic and the inevitable correction begins to take place.
5) As the correction continues the DDoS bandits realize they can create an overcorrection if they continue the attack.
And here we are.