For me, the key phrase in this article is the first one: "Faced with a dire financial situation...". The nature of working for a startup where you trade current income for potentially huge future income implies a level of risk. Looking at the breathless press coverage, it's easy to imagine that most startups are a raging success. The truth is that most will be in a "dire financial situation" and have no choice but to perform some juggling if there's any chance that they'll stay in business.
It's quite possible that the owners were deliberately trying to screw the employees, but more likely is that it's a desperate move by desperate management who are trying to salvage their dream.