Your " He was never really saved." Is a reformed line and perseverance of the saints. I totally disagree.That is down the the same lines as saying i can play on the freeway and God will take care of me.
This on going battle is one i have never been able to scripturally 'pick' a side..
One of the reason for this is the "line he was never really saved"
Eternal security is Jesus Christ preserving the believer no matter what.