Game fried my PSU, how?

I was running Anno 2070 on 2 570s and a 1000w psu, all out of sudden the computer crashed. It looked like a power failure so I ran a series of diagnostic tests on my video cards and psu. My psu has 6 6-pin connectors(4 modular and 2 connected), and I found that 2 of the modular 6-pins died because it worked when I swapped to the other 2. Hours later, the other 2 modular 6-pins died too playing the same game. I confirmed by using the 2 connected 6-pins and 2 adaptors for SLI.

Now I'm too scared to play the game again, and RMA'd the psu this afternoon, but it made no sense. I've ran bf3, which is more demanding for a month without a problem but Anno 2070 fried all modular 6-pins in less than a day? What? It baffles me...

Specs:
2700k @ 4.4ghz
Asus p8z68-v pro
hyper 212 plus
corsair vengeance 2x4gb 1600mhz
evga GTX 570 2.5gb SLI
ocz vertex 3 120gb
western digital 1tb 7200rpm
ocz z-series 1000w gold <------------NO GOOD!

I can assure you, the game (any game for that matter) was not the cause of the catastrophic failure of your PSU. I just hope the GTX 570s weren't damaged. Or anything else. Assuming all the failure was inside the PSU, you were correct in RMAing it. Assuming you didn't make a major wiring error, I'd say you were just unlucky enough to get a bad PSU.

Don't worry about any game software overtaxing your components.

Was there any visual damage you could see to the PSU, cables, connectors, cards? Burns, melted plastic? Smell any smoke or ozone?

Then my uneducated guess is that a component failed in the PSU. Possibly a capacitor or diode. Do you have a backup PSU to use while the replacement comes?

You could probably use the molex/PCIe adapters and run both cards on that PSU if it has at least 22A on the +12V rails, and has at least 2 rails. Or 44A on a single rail.