Eliezer in't a moral relativist, and does believe that there is a pattern to morality.

Eliezer is technically not a moral relativist but this is mostly a matter of that label being a terrible way to carve reality. Unless I am very much mistaken, in terms of practical connotations Eliezer's beliefs would be closer to those of a naive philosophy student who professes moral relativism than a similarly naive philosopher who professes the contrary position.