The mere fact of the Chinese accessing GM technology is obviously part of it, but this would also involve a Chinese competitor – not a joint-venture partner – ingesting a steady stream of GM's current and ongoing platforms and engineering. Since GM's shareholdings mean it needs to approve a Saab sale, the latest arrangement looks like it's going to take some reworking to come to fruition.
Saab CEO Victor Muller saying "We go back to the drawing board" is admitting that GM's stance all but unravels the Chinese agreement to purchase Saab and provide $850 million in long-term funding. We aren't entirely sure what Muller can do when he gets there: the Chinese are the only suitors on the board, no one knows if they even have government approval yet, and GM is the only company that can keep Saab in products without it costing a lot more than $850 million. But Muller's kept the ball in the air this long, we won't be the ones to count him out yet.