Downgrade pre-installed Lion to Snow Leopard on a 2011 Macbook Pro?
I'm not sure if this will work in your case. But I have a 2010 MacBook Pro I cannot install the retail copy of Snow Leopard onto. That retail disc is 10.6.3, and the laptop needs a higher version. 

To overcome this, I installed Snow Leopard on an external drive connected to an older Mac. I then updated Snow Leopard to 10.6.8 and copied the contents of that drive back to my MacBook Pro via SuperDuper.

Now, in your case, I'm not sure if Snow Leopard will work at all on the recent MacBook Pro. But, if you have access to an older Mac, give my solution a try.