QS has returned the bitcoins back to me, as requested by me on mutually agreed upon terms. Here is the relevant portions of the email exchange.
Me:
I have a request -- if I go ahead with the nuclear option , I'll need some bitcoin to finance . Do you mind returning the 20 BTC early, minus your 10%? I apologize but I've had a shift in priorities.
QS:
If you wish for me to return the 20 BTC early, then please sign a message from 16BcxMzFXxFgDPJMnsfwZ8UXh7Ly2Kew8t with the following:
Please return [amount] to and upon receipt of such BTC, Quickseller will be relieved of any further obligation to return any additional funds to the above address [dated]
Please replace [amount] and [dated] with the amount and date respectively. I will send a tx as soon as practical upon the receipt of a signed message from the above private key. If you are unable to sign a message from the above address then let me know and we can figure something out.
On a personal note, please do not take my being uncomfortable in spending your money as a sign that I do not see you as a valuable ally. The risks associated with pursuing civil litigation against Vod include the risk that my personal identity would leak even if court records are sealed as was demonstrated by how quickly he released what he believed to be my personal information. There is no doubt in my mind that Vod is going to be held responsible for his actions.
Me:
Please see the signed message below:
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Please return 18 BTC to and upon receipt of such BTC, Quickseller will be relieved of any further obligation to return any additional funds to the above address. 21/9/2015
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To which QS returned and the matter is considered settled.