I've been thinking along similar lines.... Maybe Cortese had lined up Genii/Lotus to buy out the club from the Liebherrs, when he first suspected the Liebherrs weren't prepared to inject further funds to match his desire to push the club to the next level. So, when the Liebherrs did a u-turn following Cortese's reported ultimatum (if indeed that's what they did) Genii/Lotus weren't willing to sign up for a compromise sponsorship deal.
Who knows.
Edit: pingwing's theory sounds much more likely than my random out loud thoughts!