Board Thread:General Discussion/@comment-23932365-20150118201551/@comment-3146930-20150209104006

It is possible that the gods cannot interfere directly by just flat out killing someone with the curse, but need to act by using others. We later find out in HoO that the Fates create outcomes based on certain events. Maybe Percy gaining the curse triggered a future where he couldn't be killed before the battle with Kronos at Olympus.