Is he actually saying:
"I used YOUR funds to speculate" and
"sorry - couldnt know there is risk involved. I am an experienced trader." 
Do I actually misunderstand the business model of an
escrow-service? Where the heck did you see a potential benefit for the user with the Bitcoinica adventure?
Bitcoinica went down quite a while ago - how could you cover up this mess such a long time?
I'm not trying to excuse myself, I know what I've done was wrong. I've just tried to explain my rationale - what I was thinking back then. I have had success trading on Bitcoinica with my own funds, that's why I was encouraged to try to pull of this. Now, I have a lesson learned for my whole life.
Not all funds went to Bitcoinica. There was still some left. I thought that the Bitcoinica issue will be resolved quicker so I could get the funds back. I also worked to improve the site, implemented two-auth system and other things, so the site could earn the missing coins. If it could earn money faster than people were withdrawing funds from it, this all probably could be prevented, but sadly it didn't turn out good.