https://twitter.com/#!/coda/status/182858775382851585
140 characters. Note the advanced trick he employs of explaining himself while simultaneously owning the problem. The fundamental technique there: demonstrate (somehow) that you understand the concern and that the concern is valid.
(Your annotation is more cynical than mine would be; the interesting discussion though as far as I'm concerned is "the mechanics of how to apologize effectively in an open letter").