Exactly, he asks him his name, and that is the terms of his agreement. For as long as he remains Henry Gale (in his mind) then he will look after him. He aint Henry Gale no more... he's abonded his part of the agreement, so now Locke can do the same.

Dunno wot use he'd be trying to protect him anyway, not being able to walk, against a pack of blood thirsty losties.