Because IMO, Bentham and the lawyers wanted sure payment. It was offered and accepted by Billy, as he was in debt to both. Teese's valuation was not fought for at the settlement. With Billy and Deirdre getting 42% of the gross settlement, there was no need to consider their own (and our) shares. Keep listening to those that don't know what happened, since you don't believe one that does.
All information provided is the opinion of this poster from review of information in the public domain.