I once managed to use a EULA in reverse.
I purchased MacOS 8.1 from the (then) only Apple Store, meaning the one at Apple HQ.  Then I found out I could upgrade to it for free 'cause my computer was new.  So I went to return it.  They had signs there saying they didn't take returns.  So I told the sales droid that, since they wouldn't honor their license, I would feel free to distribute their software as I wished.
Oh, they didn't like that at ALL!  Nope.  Too bad.  They had the choice of accepting the return, or violating their own EULA, which said that if I didn't accept the license, I could return the product for a full refund.  Accept it and refund the money, or the EULA is DEAD and I can do whatever I want with the product. 

  I got my money, you bet.
OTOH, I don't know what happened internally 
afterwards...