When you hit reply on a level 2 comment, the generated "reply to" link is for the user who added the level 1/0 comment, not the user who added the level 2 comment you are replying to.
When you hit reply on a level 2 comment, the generated "reply to" link is for the user who added the level 1/0 comment, not the user who added the level 2 comment you are replying to.