The lawyer’s favorite answer: It depends.  What does it depend on?  Well, what do the corporate documents say?  Was this contingency included in the firm’s Bylaws or Operating Agreement?  Did the firm follow the precise legal requirements so that the creditor cannot “pierce the veil” and get to the owner’s personal assets?  Did the creditor(s) demand a personal guarantee from the owners or someone else?  It may also depend on how much debt it is.  It is financially worth fighting about?  Sometimes it is, sometimes it isn’t.