I mean, they made a deal for what at the time was a lot of money. Should they have gotten residuals? Probably, but they had an opportunity to negotiate that and either didn't ask for them or the studio refused. They could have chosen to not take the money and shopped it to another studio, but apparently chose to take the money up front instead. I'm sure there was some evil movie studio maneuvering going on, but they really should have gotten an experienced lawyer/agent before doing the deal and they really had all the leverage whether they knew it or not.