Lee blogged his side of the story in an appropriately titled post.
So it came to pass that when my Engineering and Design team had irreconcilable differences with where the company seemed to be headed, I was asked to make good on those promises. Serving as the team’s reluctant spokesman was not in my best interests, but honor dictated my actions. I delivered the team’s message, and was invited to resign.
The rest of Lee's farewell post is an interesting read – to say the least.
It's a shame too because I really like Twinkle. It's my preferred Twitter client these days because it automatically grabs my location and makes it easy to add photos to tweets. Currently it's crashing when I add photos, so it's extra sad that Lee is gone.