Is the DBA executing the query directly at the database server and the developer from a client machine? How big is the result size? I'm asking because one reason could be that a big result is to be retrieved, and the network connection makes up for the time difference.
Another issue could be that developer and DBA have different privileges on various objects (e.g. USE privs on table spaces).
Also, have you verified that both, developer and DBA, get the same access plan for the query?