When the more-powerful owes money to the less-powerful, the debt obligation works to ensure that the less-powerful person's choices are limited to "walk away from my money" or "wait around and hope". When someone says they are going to pay you, you really really want to believe.
Funny how the debt obligation always works in the more-powerful party's favor :(
I have had a very similar situation happen twice, once when a VC gave a small startup the "check is in the mail... no wait we have to transfer money.. no wait we have to liquidate an investment" BS while the employees worked without pay for months on end. My first startup job, and the LAST time I will work for any amount of time without getting paid.
The second time (different company) the founder/VC (allegedly) defrauded the other investors by puffing up the startup's prospects, and then when the startup got acquired by ${BIGCO} for a very very low valuation only the founder walked away with any money... he was indicted, I think, I had to produce years worth of email for trial discovery and was lucky not to have to testify.
In my experience, working for a messed-up/sketchy startup is just a resume item that most people have, and you hope you only have one of...