This is critical difference. They did not make the same mistake and especially not in the same way. Patrick should have been in a position to much better understand what is happening in his business.
In an ideal world, maybe that should have been the case. But in this world, it simply wasn't.
It makes no sense to say the lenders should have understood Patricks business enough and in same detail avaliable to Patrick to be able to make the judgement.
Perhaps it makes no sense, but it was in fact true. Patrick's business model and methods weren't a secret. They in fact *did* understand Patrick's business model well enough to make the judgment. If you look, you'll find some of Patrick's lenders arguing about this very issue in this very forum.
Patrick on the other hand should have understood these issues and in the case he does not he should not have made claims about them or pay if they are false. It is much more sensible to say that some lenders should be able to take what they are being told at face value and rely on that.
If so, why can't Patrick take what his borrowers told him at face value and rely on that? Patrick made precisely the same mistake those who loaned him money did. You're excusing his lenders but not excusing him.
Each of the lenders have their own set of assumptions. I would not even claim that two different lenders did the very same mistake the very same way.
I'm not sure I know what you mean by "assumptions". But the mistake was fundamental and inherent in the business model and lending environment. The mistake was failing to realize two things:
1) There's no way to enforce these loans in any court of law. That means if people have any reason not to repay, they won't repay. Many people won't sacrifice their real-world lifestyle and bank accounts to repay a bitcoin loan that can't be enforced anyway.2) Borrowing from Patrick to invest in Pirate just seemed like too good a deal, especially since people knew they could just default on Patrick without consequences. No method would prevent this, short of actually tracking what each person did with the bitcoins, which nobody would agree to.This is why Patrick's business failed. And there is no argument you can make why Patrick should have known this that doesn't equally apply to those who loaned him money.
(And, again, this doesn't apply to Kraken, which I think was likely an outright scam.)
That's about the only thing you can blame the depositors on: blindly sending their money to anyone without researching. If you're looking at convincing people to no longer do that, don't try to twist things to make it the depositor's fault.
Believing the seller to deliver on his claims is not the same mistake as making a mistake which cause the actual loss.
Otherwise, if a loaner would tell you that he would like a loan and that he can claims he can repay it with his mining rig because it produces enough for that, and the lender agrees the proposition/proof is enough for him, if the difficulty ramps up making the loaner impossible to repay the loan by meaning, the loaner is not freed of a part of the loan value on behalf it was a common mistake. The loaner is still in debt. There is no common mistake in accepting claims by the other party which ends up being false because the buyer cannot verify that and can expect the seller to deliver upon his claims. Neither is this acceptance of the claims the direct cause of the damage.
A common mistake would be if the buyer was for example in Washington (D.C.) and the seller was in Washington (state) and was equipped to deliver in Washington (state) only. On call, both assumed they were in the same Washington when making their contract which ends up being impossible to be delivered before the cherries spoil. Since the buyer also caused the loss through his mistake because both parties did not correctly specify their exact delivery location / delivery zone, he could be judged at fault too and expected to share the loss's cost because the supplier acquired the cherries and they're spoiling. Yet seller could be considered just as much at fault for claiming he was delivering in Washington but not specifying if it was the state or the city. The common mistake of not specifying the exact location directly rendered the contract impossible to execute and caused the loss.
If the seller claims to have something he can deliver an he could execute the delivery if he's right, it does not constitute common mistake. The contract is solely impossible because the sellers fact were wrong and the buyer expected them to be right. It is akin to the seller claiming he delivers in Washington D.C. when he never could. Or someone claiming he could repair something when he does not have the knowledge to. Someone claims he'll deliver X and delivers Y. Patrick claimed to not be exposed when he was. The fact the buyer assumes the seller's statement to be right does not cause the loss or invalidates the contract because the seller could execute it but did not actually have what he claimed, then the seller is fully at tort for not delivering. If someone claims to deliver something in a contract, he's the only one to blame if he did not have the means to or it does not end up being possible. Still, pirate exposure is not even included in the contract to start with which further invalidates that as a potential common mistake. (See further below.)
Common mistake applies when the mistake cause the loss. Not when the mistake is that both believe their would be delivery without a loss while the seller and deliverer was in charge of delivery and the means to do so, and ended up failing to his promises.
The buyer's error is that the seller claims would be contractually executed. Otherwise someone telling you he'll repay you and you accepting that to loan him funds would place you at common mistake if the loaner cannot repay you (not because he willingly conned you but because he ended up not being able to collect enough money to repay you. Both of you believing that he could.) Is he freed from debt?
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So is this the same as me going to a bank, giving them $500 to open a savings account which will accrue interest and will also allow me to withdraw some or all of my $500 whenever I want, then at some point the bank says "yeah that $500, you can't withdraw that whenever like we said, but you'll still get interest on it"?
No because that doesn't have a common mistake and your bank deposit is insured. Also, you have a reasonable expectation that your bank will make only sound loans and no reason to think your bank's business model isn't sound. So it's totally different. (It would be different if, for example, you knew the bank was going to take all the money it borrowed to Vegas.)
And I'm pretty sure that's what everyone who deposited did. That they believed that Patrick could deliver what he said he's delivering, not that what he said is true. If I had chosen to accept his claims, I'd be on the belief that Patrick could deliver. I would remain in doubt he had exposure has I can't verify that and would neither claim to be true what I cannot verify.
People where lending him funds for his business like they deposit at a bank so it can do it's business of loaning funds/safekeeping. The contract was that he'd deliver X interest and would allow withdrawal anytime.
When someone accepts a claim that the seller is delivering something, he's not acknowledging that the claim is a requirement for the contract to be executed or that the claim is true. That person acknowledge that they pay for the delivery of that claim. The buyer is not at tort for believing the seller can deliver. The belief the seller would deliver is not the cause of the damage. The damage is solely on the seller's shoulder for not delivering.
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As you said however, it would be very hard to enforce in a court and as such, people might be blamed for not being careful enough as to who they extend their money to. But that doesn't free the borrowers from delivering upon their claims because the lender believed the borrower could deliver those claims. He should get a scammer tag for not delivering what he claimed he would deliver until he can deliver deposits back in full.