I really don't think the creditors can.
Tha's the power of BK court.
Look at GM and all the airlines.
At the chaotic time around 2008 and 2009, the court asked them to either sign your name to agree to $0.2 on a dollar or assume the risk of getting nothing.
You can opt out the BK proceeding and bring your own law suit, but I think very few did that.
$0.2 on a dollar (FV dollar) is really not bad at all, considered in most BK cases most creditors got nothing. So many agreed and judge approved it.
Once we pay off the POR, Lehman is a free bird again.