Did they not get screwed, though?

As far as I could tell from the article, StartEngine's contract was solid. The Style Club LA had no legal right to transfer assets and IP to a new company without permission from StartEngine, which they did not receive.

So Cuban and Shark Tank invested in a company which came to them under false pretenses, with a significant undisclosed liability. If that's the case, they absolutely got screwed - they probably aren't culpable for Style Club's lack of disclosure, but they did get tricked into a bad investment.