BuddyPress.org

If you look at the “View” link output, it is fine–no double comment reference. It is only the Blog title link that has the doubling error.

The error is caused by the Comment ID being passed twice into the sprintf() function. One time from the line above via the $comment_link variable, and the second time directly within the function via ‘#comment-‘ . $comment->comment_ID. Therefore, removing the second reference is the better option.

The way that you are currently doing it may work, but once you upgrade BuddyPress, your changes will be lost. That is why it is important to file bug tickets and get the bugs correct in the core files!