I tend to agree. Dagny would be choosing whom to work with based on their having a vested interest in the success of the enterprise. There is no reason to fear a "double-cross" from someone who gains when you gain.
she was talking to her brother James when she made the double-cross statement. she wants to save CO with the John Galt line made of Rearden Metal and she breaks off the company to keep James and the Board from micro-managing her with a promise to give it back when she has succeeded. But she knows that James could double-cross her...
I kind of think she said something similar to Jim Taggart when she was doing something with stock-shares to finance the John Galt line and she was forced to trust him when she knew perfectly well he was untrustworthy.