This just happened:
INBOX
(Programmers SE item) answer migrated 2 hours ago Your answer to "Testing a method that reads from standard input and outputs to standard output" was migrated to Stack Overflow.
ACHIEVEMENTS
(Programmers SE item) You've earned the "Disciplined" badge (Deleted own post with score of 3 or higher) for "Testing a method that reads from standard input and outputs to standard output".
Needless to say, I did not delete my own post. Apparently, the migration was counted as deletion, and for this reason the "Disciplined" badge was awarded.
On second thought, thisissuchanunimportantbug.
noneedtodoanythingaboutitreally.