James gave his life, why no protection from him?

[jakedjensen]

No: HPFGUIDX 106545

I just got done reading PoA (again) and a thought occurred to me. 
Lily gave her life to protect HP and that resulted in magical 
protection for HP. But James did the same thing only moments before 
(for both Lily and HP). So, even if it is a matter of blood (as DD 
suggests at the end of OoTP), James act should still have protected 
HP (unless we are led to believe that James didn't love HP or 
something...highly unlikely I think). So,

(1) Lily must have done something more than just give her life for 
HP, becaue James did that and nothing happened.

or 

(2) there something about Lily that allows her to do this.

Thoughts?

Jake