I'm looking at the following from the post:

> The intrusion originated on May 5 when a build deployed to the development tier for stackoverflow.com contained a bug, which allowed an attacker to log in to our development tier as well as escalate their access on the production version of stackoverflow.com. > Between May 5 and May 11, the intruder contained their activities to exploration

To me, that reads "we deployed a bug on May 5th that allowed intrusion, and it was exploited the same day." If that's not what they meant - I certainly recant my criticism - but "on May 5th when a build deployed contained a bug" is difficult for me to interpret differently.