User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-122.164.246.114-20121221062619/@comment-3146930-20121223022925

According to Sammy, Hera appeared to him for whatever reason and told Sammy that he would not live long enough to help Hazel when she faced her great danger. So he asked Leo to be his stunt double, helping Hazel where he couldn't. It wasn't to break her curse, it was simply to help her because he couldn't.