No, either person could have been handling pilot, or PIC. In fact the flight may have had nothing to do with the rating being revalidated.
Don't have a reference for that, just a recollection of reading it. What I mean though, is that an instructor carrying out the training flight for revalidation, doesn't have to sign the person's logbook. If you are the FE/CRE then yes, if the logbook has the required experience, then revalidate the rating.