I've noticed that Super User has granted me two "Nice Answer" badges.

Yet I can only see one answer of my own which would appear to qualify. Additionally, I seem to have a "Good Answer" badge on Super User which I do not appear to deserve at all. :)

Checking the vote counts on the other highest-voted answers I have there, it doesn't appear to be a case where I had an answer that was upvoted above 10, then downvoted below. Ditto (naturally) the 25-vote threshold for "Good Answer."

Do I have answers which were perhaps deleted (or on questions which were deleted/migrated) that garnered the requisite upvotes for these badges? Do I merely "owe" the system them?