I believe the sort=votes parameter is for when you are retrieving multiple questions in one API call, such as with this URL - the questions in the response are ordered by vote.

http://api.stackoverflow.com/0.8/questions/1429951;2383701;619895?sort=votes&type=jsontext

I believe the sort=votes parameter is for when you are retrieving multiple questions in one API call, such as with this URL - the questions in the response are ordered by vote.

http://api.stackoverflow.com/0.8/questions/1429951;2383701;619895?sort=votes&type=jsontext

In terms of how you could sort the responses - you do have the up + the down vote count from which you could sort on your application side, or you could make another request to the api with the extracted answer IDs and sort=votes, which is really a waste of resources when you already have all the data.