For a systematic review, it is strongly recommended that search strategies be peer-reviewed before the searches are conducted.
"The PRISMA-S extension states that authors "should strongly consider having the search strategy reviewed by an experienced researcher, information specialist or librarian" and encourages authors to consider using the Peer Review of Electronic Search Strategies (PRESS) Guideline Statement" (Cochrane Handbook for Systematic Reviews of Interventions version 6.3).
My question is, can this experienced researcher be a co-author of the review?