How do you know the crash was caused by someone dumping 69k coins at market? Is this a verifiable fact or speculation on your part?
If speculation, why do you believe someone did this?
I don't understand who in their right mind would do such thing?
I mean it's a very poor way to sell a position so large, right? Since you will get serious slippage?
Of course there is a verifiable fact. Just check the "trade history" on bitcoincharts or similar, or follow the "time & sales" on http://bitcoin.clarkmoody.com/. I was trading when that happened, in fact I was very happy because of the unbelievable buying opportunity until Gox fucked up and halted trading to induce "market cooldown". You can check the forums and you will see I was the first one to post about this "market cooldown"
I had to wake up at 4AM to be ready when Gox reopened, just to see how my big buy order at 35€ was not fulfilled for just a couple of euros (bottom in € was 37€). That really pissed me off, I think I should trade in USD, as it's much easier to spot support and resistance points.
Doubtful, if you have followed this market for long, you will know that at certain price points the buying/selling volume will spike up, probably bots triggered by price movement, the same thing may happened during the crash.