That is correct. What the complaint alleges is that Goldman told the Marvell founders that they had to sell shares of their own company bought with their margin account (borrowed money) to comply with an SEC rule that stocks purchased with margin accounts must be sold when they fall below $5 in value, which Marvell did during 2008. According to the complaint, there is no such SEC rule.
The article's "marginal call" refers probably to a margin call, i.e. forcing the Marvell guys to sell some of their stock to replenish their cash account. This can happen when they leverage, i.e. borrow money from their broker to buy a lot of stock they expect to go up---but when the stock goes down instead, suddenly the loan-to-equity ratio shoots up and the banking regulations require shoring up of the equity by pumping cash into the client's account, typically by selling. Highly unpleasant but not unexpected. GS probably bought their own shares of NVIDIA with cash so they didn't need to margin call itself.
I am no G-S fan, but superficially, this looks like bad risk management, and possibly bad advice rather than fraud.