You skipped over one of the important questions - who was lied to, and about what?
As for the "closed source" nature of CDOs, it's irrelevant. I've read a few CDO prospectuses. They all are pretty clear about the fact that the purchaser is taking out a long position on housing. If you lost money on securitized debt, it's because the instruments behaved exactly as they were supposed to: housing goes up and you win, housing goes down and you lose.
CDOs are also explicitly not closed source - the purchaser gets a detailed listing of every single item it's value is derived from and the exact set of rules that will be applied to determine who gets a payout.
After that, the salespeople sold them as AAA. That implies to the person buying that it's extremely unlikely to default, generally less than 1% risk. Given that the bankers structuring these had very good reason to suspect that that wasn't true, I'd say that counts as a lie. You're making it sound as though this was supposed to be a risky bet, and that the pension funds simply lost the bet. That's not at all what AAA means. Funds were sold exploding lemons by people who should have known and probably did know that they were lemons.
For CDOs based on other, well understood securities, you're right. In the case of CMOs, most of them did not contain more than cursory information about the underlying mortgages, if that.
If you're looking for a specific instance of a lie, as in Person X told Person Y XYZ, I don't have that for you, and if I did, I wouldn't share it with you. But based on how these things work, there's little doubt in my mind that these things were knowingly misrepresented by a large number of people, which I believe is the definition of fraud.
Many of the banks have claimed that since the regulators rated these things well, why should they be held accountable? The buyer is supposed to be educated if they're playing in this league, caveat emptor (this is a pervasive attitude in banks). I think that's bullshit, because when the banks securitize this stuff, they're abstracting away the underlying layers, and it's effectively closed source. But people seem to have bought into it.
To answer your questions, pension funds and others poured hundreds of billions into CDOs as a result (many legally wouldn't have been able to unless the banks got them to AAA). A huge percentage of these assets lost a huge amount of value. One of the net results was an extremely large wealth transfer from pension funds and governments to bank employees.