Read more: Rick Santorum Is Right: Gas Prices Caused the Great Recession (theatlantic.com)
As the more thoughtful poster stated, it may have not been the gas can, but it certainly was the match!
1. Everyone was buying land & homes for ridiculous price. It did not matter if you could afford them or not. Undeveloped farmland in the middle of nowhere was bringing 8k to 10k per acre ten times what you would normally expect to pay.
2. Everybody, Bankers included believed we were in a state of Nirvana property values would never go down.
3. Homes were being used as every ones on personal ATM. There was no reason to pay down or pay extra there was better thing to the spend money on.
The Housing bubble would have burst even if Gas had been given away for free.